Sample Vial Research Articles

Laser-induced nucleation of urea through the control of Insoluble Impurity

The mechanism of non-photochemical laser-induced nucleation (NPLIN) was investigated through the crystallization of urea crystals in supersaturated (151%) aqueous solutions. To detect the role of impurities in NPLIN, the effect of filtration, doping and laser irradiation position on nucleation probability were studied, respectively. As particles larger than the filter pore size in the solution were almost removed by syringe filter with poly (ether sulfone) membrane, the NPLIN probability was evidently suppressed by filtration when the pore sizes of filter were used from 1 μm to 0.45 μm. The inhibition of NPLIN after filtration could be reversed to varying degrees by adding several kinds and concentrations of impurities into the filtered solution; as the solid particles were extra added, age after cooling for samples was no longer necessary. The increase in the NPLIN probability with the irradiation height decreases was observed when samples were irradiated at different vertical positions within the sample vial. The experimental results were analyzed with reference to the known mechanisms. As nucleation probability through NPLIN can be controlled by pore size of syringe filter, doping or laser irradiation position, several functions were established to analyze the nucleation probability distribution under the effect of these three factors. These experimental results were discussed with reference to the known mechanisms proposed for NPLIN.

Real-time automated quality control for quantitative MRI.

This work presents an automated quality control (QC) system within quantitative MRI (qMRI) workflows. By leveraging the ISMRM/NIST quantitative MRI system phantom, we establish an open-source pipeline for rapid, repeatable, and accurate validation and stability tracking of sequence quantification performance across diverse clinical settings. A microservice-based QC system for automated vial segmentation from quantitative maps was developed and tested across various MRF acquisition and protocol designs, with reports generated and returned to the scanner in real time. The system demonstrated consistent and repeatable value segmentation and reporting, successfully extracted all 252 T1 and T2 vial samples tested. Values extracted from the same sequence were found to be repeatable with 0.09% ± 1.23% and -0.26% ± 2.68% intersession error, respectively. By providing real-time quantification performance assessment, this easily deployable automated QC approach streamlines sequence validation and long-term performance monitoring, vital for the broader acceptance of qMRI as a standard component of clinical protocols.

B-148 Bacer: decentralized isotope dilution method with lab blinding for blood alcohol content

Abstract Background In legal medicine, the determination Blood Alcohol Content (BAC) usually faced the problems of insufficient sample size, ethanol degradation and impossible double check. In addition, the integrity of laboratory may also be questioned. To this end, we developed a decentralized solution based on isotope dilution method. Methods Patented deuterated ethanol vacuum tube was used in field as regular type, weight of blood was record to BACer terminal. Arbitrary amount of sample(ca.0.1-1.0g) was pipetted to GC sample vial and sealed tightly, then heated more than 2min at 70°C, 10µL headspace sample was injected into GC-MS. Blinded lab uploaded peak area ratio of ethanol/deuterated ethanol(mz31/33) to BACer to calculate the final BAC. Results Regression between peak area ratios of ethanol/deuterated ethanol showed good linearity in the range of 0.10-5.0 (R2>0.999). Regression equation of different instruments were proved good consistency with slopes ranged from 1.03 to 1.07, and the LOD and LOQ were around 0.01mg/g and 0.05mg/g, 3-level recoveries between 97%-101% with RSD less than 1%. During the 6-month stability test at 4°C and normal temperature, the blood sample test results maintained good stability. The proposed method was applied to 2021 CNAS proficiency testing (2021SF-CNAS002) organized by China Academy of Forensic Sciences with satisfactory results. The comparison with Chinese standard method SF/Z JD0107001-2010 yielded good agreement with Passing&Bablok test (P>0.10). The expanded uncertainty estimated by Monte-carlo method was less than 3%. Conclusions This proposed method showed the possibility of decentralized determination of BAC with lab blinding, the separation of on-site sampling data and laboratory testing also provided the possibility of integrity of results. It also provided a possible solution for the scenarios where the storage condition of blood collection is poor, or the cross check is required. But good chromatographic separation and operation are compulsive due to the possibility of interference in IDMS.

Evaluating the relaxation effects of Shikuwasa (Citrus depressa Hayata) essential oil inhalation in young female adults: Study protocol for a randomised controlled trial

IntroductionThe essential oil of Shikuwasa (Citrus depressa Hayata) primarily contains limonene and γ-terpinene, which have potential applications in stress management and relaxation. However, the psychological or physiological relaxation effects of Shikuwasa essential oil on humans are still unknown. This study aims to investigate the short-term relaxation effects of Shikuwasa essential oil, one of the less-studied varieties, compared to inhaling odour-free air in young female adults. Methodsand analysis: This study is a two-arm, parallel-group, open-label, randomised controlled superiority trial. Forty young female adults will be assigned with a 1:1 allocation ratio to either the Shikuwasa essential oil inhalation group or the odour-free air inhalation group. The primary outcome measure will be subjective tense arousal (subscale of the Japanese version of the University of Wales Institute of Science and Technology Mood Adjective Checklist). Secondary outcomes include objective measures: miosis rate and peripheral skin temperature for evaluating autonomic nervous activity, and cerebral blood flow (assessed using near-infrared spectroscopy) for evaluating central nervous activity. Since these objective outcome measures cannot be performed at the same time, we divide our experiment into three phases and participants will inhale sample vials for 2 min in each experiment. We will also evaluate individual preferences/impressions regarding inhaled samples and any adverse events. Ethics and disseminationThe study protocol has been reviewed and approved by the Research Ethics Committee of the Faculty of Medicine, University of Miyazaki (reference no: I-0074). The findings of this study will be disseminated to academic and professional audiences via publications in peer-reviewed journals and presentations at academic conferences, and to the broader public via public talks and media/press releases. All study findings, whether negative or positive, will be reported. Trial registrationUMIN Clinical Trials Registry (UMIN-CTR), UMIN000053914. Prospectively registered on March 20, 2024.

Radon leakage in LSC vials: Material-dependent analysis for utilization and reutilization

Liquid scintillation counting (LSC) is a method commonly used for natural occurring radionuclides measurements in water, in which radon concentration is measured after placing water samples in LSC vials that contain scintillation cocktails. Due to the low levels of activity that are involved in natural environments, it is required to characterize any radon loss during the measuring process in order to minimize errors and uncertainties. Hence, radon leakage in different types of vials (plastic and plastic lined with Teflon) is studied. This analysis reported that, after one and a half radon half-lifes, plastic and Teflon lined vials, compared with the values expected for no radon leakage, presented deviations in radon concentration over the 7% and 3%, respectively. Additionally, the diffusion of radon through the vials' wall is checked, as well as if it remains embedded in the polymeric matrix. This study confirmed that radon remains embedded in the polymeric matrix and can diffuse back to the vial, having the plastic vials a greater contribution. The possibility to re-utilize single-use vials is also studied from characterizing the presence of radon depending on the vial's material.

Pre-analytical challenges from adsorptive losses associated with thiamine analysis

Thiamine (vitamin B1) is an essential vitamin serving in its diphosphate form as a cofactor for enzymes in the citric acid cycle and pentose-phosphate pathways. Its concentration reported in the pM and nM range in environmental and clinical analyses prompted our consideration of the components used in pre-analytical processing, including the selection of filters, filter apparatuses, and sample vials. The seemingly innocuous use of glass fiber filters, glass filter flasks, and glass vials, ubiquitous in laboratory analysis of clinical and environmental samples, led to marked thiamine losses. 19.3 nM thiamine was recovered from a 100 nM standard following storage in glass autosampler vials and only 1 nM of thiamine was obtained in the filtrate of a 100 nM thiamine stock passed through a borosilicate glass fiber filter. We further observed a significant shift towards phosphorylated derivatives of thiamine when an equimolar mixture of thiamine, thiamine monophosphate, and thiamine diphosphate was stored in glass (most notably non-silanized glass, where a reduction of 54% of the thiamine peak area was observed) versus polypropylene autosampler vials. The selective losses of thiamine could lead to errors in interpreting the distribution of phosphorylated species in samples. Further, some loss of phosphorylated thiamine derivatives selectively to amber glass vials was observed relative to other glass vials. Our results suggest the use of polymeric filters (including nylon and cellulose acetate) and storage container materials (including polycarbonate and polypropylene) for thiamine handling. Losses to cellulose nitrate and polyethersulfone filters were far less substantial than to glass fiber filters, but were still notable given the low concentrations expected in samples. Thiamine losses were negated when thiamine was stored diluted in trichloroacetic acid or as thiochrome formed in situ, both of which are common practices, but not ubiquitous, in thiamine sample preparation.

Development of a fast‐response system with integrated calibration for high‐resolution mapping of dissolved methane concentration in surface waters

AbstractDissolved gas concentrations in surface waters can have sharp gradients across marine and freshwater environments, which often prove challenging to capture with analytical measurement. Collecting discrete samples for laboratory analysis provides accurate results, but suffers from poor spatial resolution. To overcome this limitation, water equilibrators and gas membrane contactors (GMCs) have been used for the automated underway measurement of dissolved gas concentrations in surface water. However, while water equilibrators can provide continuous measurements, their analytical response times to changes in surface water concentration can be slow, lasting tens of minutes. This leads to spatial imprecisions in the dissolved gas concentration data. Conversely, while GMCs have proven to have much faster analytical response times, often lasting only a few minutes or less, they suffer from poor accuracy and thus require routine calibration. Here we present an analytical system for the high accuracy and high precision spatial mapping of dissolved methane concentration in surface waters. The system integrates a GMC with a cavity ringdown spectrometer for fast analytical response times, with a calibration method involving two Weiss‐style equilibrators and discrete measurements in vials. Data from both the GMC and equilibrators are collected simultaneously, with discrete vial samples collected periodically throughout data collection. We also present a mathematical algorithm integrating all data collected for the routine calibration of the GMC dataset. The algorithm facilitates comparison between the GMC and equilibrator datasets despite the substantial differences in response times (0.7–2.1 and 4.1–17.6 min, respectively). This measurement system was tested with both systematic laboratory experiments and field data collected on a research cruise along the US Atlantic margin. Once calibrated, this system identified numerous sharp peaks of dissolved methane concentration in the US Atlantic margin dataset that would be poorly resolved, or outright missed with previous measurement techniques. Overall, the precision and accuracy for the technique presented here were determined to be 11.2% and 10.4%, respectively, the operating range was 0–1000 ppm methane, and the e‐folding response time to changes in dissolved methane concentration was 0.7–2.1 min.

Solid-Phase Microextraction-Aided Capillary Zone Electrophoresis-Mass Spectrometry: Toward Bottom-Up Proteomics of Single Human Cells.

Capillary zone electrophoresis-mass spectrometry (CZE-MS) has been recognized as a valuable technique for the proteomics of mass-limited biological samples (i.e., single cells). However, its broad adoption for single cell proteomics (SCP) of human cells has been impeded by the low sample loading capacity of CZE, only allowing us to use less than 5% of the available peptide material for each measurement. Here we present a reversed-phase-based solid-phase microextraction (RP-SPME)-CZE-MS platform to solve the issue, paving the way for SCP of human cells using CZE-MS. The RP-SPME-CZE system was constructed in one fused silica capillary with zero dead volume for connection via in situ synthesis of a frit, followed by packing C8 beads into the capillary to form a roughly 2 mm long SPME section. Peptides captured by SPME were eluted with a buffer containing 30% (v/v) acetonitrile and 50 mM ammonium acetate (pH 6.5), followed by dynamic pH junction-based CZE-MS. The SPME-CZE-MS enabled the injection of nearly 40% of the available peptide sample for each measurement. The system identified 257 ± 24 proteins and 523 ± 69 peptides (N = 2) using a Q-Exactive HF mass spectrometer when only 0.25 ng of a commercial HeLa cell digest was available in the sample vial and 0.1 ng of the sample was injected. The amount of available peptide is equivalent to the protein mass of one HeLa cell. The data indicate that SPME-CZE-MS is ready for SCP of human cells.

Spectral Analysis of Injectable Depot Medroxyprogesterone Acetate From the International Market With Diffuse Reflectance Spectrometers: Potential Public Health Implications With Benchtop and Handheld Spectrometers

Depot-medroxyprogesterone acetate (DMPA) is an essential medication used as a form of family planning by millions around the world. Diffuse reflectance spectroscopy (DRS) has a long history as a quality assurance measure for raw ingredient verification in pharmaceutical manufacturing. There are a multitude of DMPA manufacturers in the global marketplace. Prudent supply chain management requires identification of potential suppliers that can be contacted if a current supplier is unavailable. Here, DRS data were collected with benchtop (350–2500 nm) and handheld (900–1700 nm) spectrometers for 16 brands of DMPA. Spectra from sample vials ( N = 262) are compared through principal component analysis and Mahalanobis distances. The benchtop spectrometer proved to be an efficient gauge of the similarities and differences amongst DMPA brands, with subcontracted manufacturers resulting in very similar results to the primary manufacturers. The handheld spectrometer offers advantages in portability and cost and was shown to be an effective brand discrimination tool but was less reliable in the context of identifying potentially suitable supply chain substitution options of DMPA due to several key DMPA spectral features appearing just outside of the handheld spectrometer's range. Data collected from the benchtop spectrometer was used to identify several potential supply chain substitutions, dependent on various other subsequent due-diligence activities (i.e., product documentation reviews and manufacturing site audits). These potential substitutions can be shortlisted for further auditing review prior to being identified as a potential supply chain substitution.

Correlation of Escherichia coli inactivation with histotripsy bubble cloud size

Bacterial loads can be effectively reduced with cavitation-mediated focused ultrasound, or histotripsy. Our previous in vitro work with Escherichia coli (E. coli) established strong trends of bactericide with increasing peak negative pressure amplitude, pulse length, PRF, and treatment time. The current study correlates bactericide as a function of the histotripsy bubble cloud size produced for these treatment parameters at several frequencies. Histotripsy was applied to E. coli suspensions in 10-ml sample vials at 810 kHz, 1.2 MHz, or 3.25 MHz for 40 min. Separately, cavitation was recorded using a Photron Fastrax high-speed camera for acoustic parameters equivalent to those used in the E. coli studies. The images were used to quantify the maximum size of each bubble cloud, with the assumption that the cloud was axially symmetric around the propagation direction. A strong linear relationship exists between log kill versus cloud size (R2 = 0.96). Remarkably, across all variables studied, the log-reduction in viable bacteria exhibited a direct proportional relationship with the dimensions of the bubble cloud. This strong correlation between bacterial reduction and cavitation bubble cloud size could have significance for clinical applications where bacteria cannot easily be sampled. [Work supported by NIH R01AR080120 and R01EB023910.]

Urine Self-Sampling Kit Combined with an Automated Preparation-Sampler Device for Convenient and Reliable Analysis of Arsenic Metabolites by HPLC-ICPMS.

Speciation analysis of arsenic in urine is essential for the studies of arsenic metabolism and biological effects, but the unstable arsenic species represented by MMAIII and DMAIII pose a huge challenge to analytical accuracy. Herein, a novel urine self-sampling (USS) kit combined with an automated preparation-sampler (APS) device is rationally designed and used for convenient analysis of arsenic metabolites by high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICPMS). The subject can collect urine into a sampling vial at home and use a homemade syringe to pump argon to displace oxygen in the vial, thereby inhibiting the oxidation of MMAIII and DMAIII. After USS and transportation, the sampling vial is loaded directly onto the APS device, where the urine sample can be automatically mixed with diluent, filtered, and loaded into HPLC-ICPMS for arsenic speciation analysis under anaerobic conditions. For a single sample, the sampling time and the analysis time are <8 and <18 min, respectively. The recoveries of MMAIII and DMAIII in urine over 24 h at 4 °C are 86 and 67%, surpassing the conventional sampling method by 28 and 67%, respectively. When the APS is coupled to HPLC-ICPMS, the detection limits of AsC, iAsIII, MMAIII, DMAV, MMAV, DMAIII, and iAsV are 0.03-0.10 μg L-1 with precisions of <10%. The present method provides a convenient and reliable tool for the storage and analysis of unstable arsenic species in urine and lays the foundation for studying the metabolic and biological effects of methylated trivalent arsenicals.

Magnetic hybrid Pd/Fe-oxide nanoparticles meet the demands for ablative thermo-brachytherapy

Objective To investigate the potential of hybrid Pd/Fe-oxide magnetic nanoparticles designed for thermo-brachytherapy of breast cancer, considering their specific loss power (SLP) and clinical constraints in the applied magnetic field. Methods Hybrid nanoparticles consisting of palladium-core and iron oxide shell of increasing thickness, were suspended in water and their SLPs were measured at varying magnetic fields (12–26 mT peak) and frequencies (50–730 kHz) with a commercial alternating magnetic field generator (magneTherm™ Digital, nanoTherics Ltd.). Results Validation of the heating device used in this study with commercial HyperMag-C nanoparticles showed a small deviation (±4%) over a period of 1 year, confirming the reliability of the method. The integration of dual thermometers, one in the center and one at the bottom of the sample vial, allowed monitoring of homogeneity of the sample suspensions. SLPs measurements on a series of nanoparticles of increasing sizes showed the highest heating for the diameter of 21 nm (SLP = 225 W/g) at the applied frequencies of 346 and 730 kHz. No heating was observed for the nanoparticles with the size <14 nm, confirming the importance of the size-parameter. The heating ability of the best performing Pd/Fe-oxide-21 was calculated to be sufficient to ablate tumors with a radius ±4 and 12 mm using 10 and 1 mg/mL nanoparticle concentration, respectively. Conclusions Nanoparticles consisting of non-magnetic palladium-core and magnetic iron oxide shell are suitable for magnetic hyperthermia/thermal ablation under clinically safe conditions of 346 kHz and 19.1 mT, with minimal eddy current effects in combination with maximum SLP.

Automated, cryogen-free headspace-trap with gas chromatography-mass spectrometry analysis of ethylene oxide and 2-chloroethanol as residual fumigants in foods

Ethylene oxide (EtO), although banned for use, is still being detected in foodstuffs that have been fumigated to eradicate pests during storage and transport. Residual levels over the European Union’s (EU) maximum residue limit (MRL) pose severe health concerns. Recent detection of EtO and its by-product 2-chloroethanol (2-CE) at alarming levels have led to product recalls throughout the EU. Here, a simple, automated headspace (HS)-trap method for the simultaneous determination of EtO and its derivative 2-CE by gas chromatography-mass spectrometry (GC-MS) at the required MRL of ≤ 0.05 mg/kg has been implemented. Syringe-based HS combined with backflushed trapping technology provided enrichment of multiple extractions from the same sample vial (known as multi-step enrichment or MSE®) to increase sensitivity for EtO and 2-CE analysis by GC-MS using single-ion-monitoring (SIM) mode. Method detection limits (MDLs) of 0.00059 mg/kg and 0.00219 mg/kg for EtO and 2-CE, respectively, were obtained without the need for manual handling, solvent extraction or derivatization methods. Recoveries were shown to average (n = 5) at 98% and 107% for EtO and 2-CE, respectively, and the reproducibility was <10% for both compounds.

Histotripsy-induced bactericidal activity correlates to size of cavitation cloud in vitro.

Large abscesses are walled-off collections of pus and bacteria that often do not respond to antibiotic therapy. Standard of care involves percutaneous placement of indwelling catheter(s) for drainage, a long and uncomfortable process with high rehospitalization rates. The long-term goal of this work is to develop therapeutic ultrasound approaches to eradicate bacteria within abscesses as a noninvasive therapeutic alternative. Inertial cavitation induced by short pulses of focused ultrasound (histotripsy) is known to generate lethal mechanical damage in bacteria. Prior studies with Escherichia coli (E. coli) in suspension demonstrated that bactericidal effects increase with increasing peak negative amplitude, treatment time and duty cycle. The current study investigated correlates of bactericidal activity with histotripsy cavitation cloud size. Histotripsy was applied to E. coli suspensions in 10-mL sample vials at 810 kHz, 1.2 MHz, or 3.25 MHz for 40 minutes. The cavitation activity in the sample vials was separately observed with high-speed photography. The cavitation cloud area was quantified from those images. A linear relationship was observed between bacterial inactivation and cavitation cloud size (R2 = 0.96), regardless of the acoustic parameters (specifically frequency, pulse duration and power) used to produce the cloud.

A paper-based dual functional biosensor for safe and user-friendly point-of-care urine analysis.

Safe, accurate, and reliable analysis of urinary biomarkers is clinically important for early detection and monitoring of the progression of chronic kidney disease (CKD), as it has become one of the world's most prevalent non-communicable diseases. However, current technologies for measuring urinary biomarkers are either time-consuming and limited to well-equipped hospitals or lack the necessary sensitivity for quantitative analysis and post a health risk to frontline practitioners. Here we report a robust paper-based dual functional biosensor, which is integrated with the clinical urine sampling vial, for the simultaneous and quantitative analysis of pH and glucose in urine. The pH sensor was fabricated by electrochemically depositing IrOx onto a paper substrate using optimised parameters, which enabled an ultrahigh sensitivity of 71.58 mV pH-1. Glucose oxidase (GOx) was used in combination with an electrochemically deposited Prussian blue layer for the detection of glucose, and its performance was enhanced by gold nanoparticles (AuNPs), chitosan, and graphite composites, achieving a sensitivity of 1.5 μA mM-1. This dual function biosensor was validated using clinical urine samples, where a correlation coefficient of 0.96 for pH and 0.98 for glucose detection was achieved with commercial methods as references. More importantly, the urine sampling vial was kept sealed throughout the sample-to-result process, which minimised the health risk to frontline practitioners and simplified the diagnostic procedures. This diagnostic platform, therefore, holds high promise as a rapid, accurate, safe, and user-friendly point-of-care (POC) technology for the analysis of urinary biomarkers in frontline clinical settings.

Improving hydrodynamic injection in capillary electrophoresis by using the integral of pressure.

A careful analysis of the typical devices and conditions used during hydrodynamic injection in capillary electrophoresis shows that the Hagen-Poiseuille model for the laminar flow is valid, even during the transitions of pressure. Therefore, the monitoring of pressure becomes a reliable approach to evaluate the effective injected volume, because the volume is proportional to the integral of pressure (IoP) over time. A piezoresistive sensor was used to monitor the air pressure at headspace of the sample vial. A set of 18 injections at 50mbar and different times were used to evaluate the use of the normalization of the peak areas of the analytes by the IoP to compensate for imperfection during the injection. There was a significant decrease in relative standard deviation (RSD), and the proposed approach presented results similar to the use of internal standard. In addition, a microcontroller was used not only to monitor the pressure but also to command a peristaltic pump and a solenoid valve creating a system that dynamically controls the applied pressure and stops the injection when the desired value of IoP is reached. The system was used in a proof of concept in which different combinations of pressure and time were used: 10mbar×50s, 25mbar×20s, 50mbar×10s, 125mbar×4s, and 250mbar×2s. Despite the constraints posed by the flowrates of the peristaltic pump and the solenoid valve, the microcontroller effectively conducted the injections across this extensive range of conditions, resulting in an IoP RSD of 2.7%.

Catechu (Senegalia catechu) based oxygen scavenger for active food packaging: A sustainable alternative

For the first time, a novel oxygen scavenging system (OSS) based on Acacia catechu (AC) and calcium carbonate (CC) was developed, and its oxygen scavenging ability was evaluated. At day 0, the oxygen content in the sample vials was 20.9%, which decreased to 12.7% and 8.3% over 20 days at 25 °C and 60 °C, respectively. The effect of concentrations of both components was analyzed by comparing final oxygen values (%) for AC1-CC1 to AC5-CC1 and control samples. The highest reduction (%) was recorded in samples AC1-CC1, which had an equal mass of both components compared to all other samples stored at the same temperature. The developed OSS demonstrated an oxygen absorption capacity of 10 ± 1.13 mL O2/g and 15.56 ± 0.51 mL O2/g at 25 °C and 60 °C respectively, whereas the reported oxygen scavenging rate for the same is 0.5 ± 0.05 mL O2/(g day) and 0.77 ± 0.02 mL O2/(g day). The observed rate constant values increased with increasing temperature from 0.02113 to 0.02350 (h−1) at 25 °C and 60 °C. Therefore, the findings of the present study demonstrated that AC–CC–based OSS with moisture activation is a suitable natural alternative to chemical-based oxygen scavengers for long-term stored foods with a moderate to high susceptibility towards oxygen.

Quantitative Analysis of Acetyl-CoA, Malonyl-CoA, and Succinyl-CoA in Myocytes.

Several analytical challenges make it difficult to accurately measure coenzyme A (CoA) metaboforms, including insufficient stability and a lack of available metabolite standards. Consequently, our understanding of CoA biology and the modulation of human diseases may be nascent. CoA's serve as lipid precursors, energy intermediates, and mediators of post-translational modifications of proteins. Here, we present a liquid chromatography-mass spectrometry (LC-MS) approach to measure malonyl-CoA, acetyl-CoA, and succinyl-CoA in complex biological samples. Additionally, we evaluated workflows to increase sample stability. We used reference standards to optimize CoA assay sensitivity and test CoA metabolite stability as a function of the reconstitution solvent. We show that using glass instead of plastic sample vials decreases CoA signal loss and improves the sample stability. We identify additives that improve CoA stability and facilitate accurate analysis of CoA species across large sample sets. We apply our optimized workflow to biological samples of skeletal muscle cells cultured under hypoxic and normoxia conditions. Together, our workflow improves the detection and identification of CoA species through targeted analysis in complex biological samples.

A-361 Implementation of a Fit-for-purpose Point of Care Quality Assurance Program

Abstract Background All individuals should have equitable access to accurate and timely testing for infectious diseases. Point of care testing (PoCT) has been developed to support populations having limited access to laboratory-based testing. Unlike laboratory-based testing, PoCT is often performed by non-laboratory staff and outside the jurisdiction of regulatory frameworks. Under these conditions, quality assurance (QA) of PoCT is often lacking; inaccurate testing can go undetected, leading to poor patient outcomes. A fit-for-purpose QA program was developed to monitor the quality of PoCT for infectious disease testing, particularly in low-middle income countries and in testing outside the laboratory regulatory environment. Methods In collaboration with the World Health Organization (WHO), the National Serology Reference Laboratory (NRL) reviewed the barriers to participation in QA programs experienced by PoCT sites. Using this information, NRL developed a QA model specifically designed for PoCT for infectious disease. In collaboration with Foundation for Innovative and New Diagnostics (FIND, Geneva, Switzerland), Kirby Institute (Sydney, Australia) and Flinders University (Adelaide, Australia), NRL implemented the PoCT QA model across Africa, Asia, and remote regional Australia. The model consists of competency panels (CP - one positive and one negative sample) and external quality assessment (EQA) panels. The EQA panels contain five samples. Whereas the test site knows the reactivity of the CP samples, the EQA samples are tested blinded. Both panels use inactivated samples that are stable at ambient temperature. The model uses streamlined logistics channels, with data collection and analysis using smartphone technology and QR codes. NRL designed a method for randomizing the identity of EQA sample vials so test sites can test QA panels ad hoc, and not be limited to specific test event dates. A range of support material such as pictorial instructions for use, virtual training events and on-line videos were produced to support test sites. Results More than 100 test sites from 14 countries have participated in the NRL PoCT QA programs. The model is designed so data is collected by test sites scanning QR codes and entering results directly into a data entry screen. The NRL PoCT QA program removed barriers to participation by offering sample types that are inactivated and stable at ambient temperature for extended periods of time, removing the need for dry ice shipping. The program is cost effective making it accessible to low- and middle-income countries. Data is collected using novel smartphone technology, facilitating results to be entered into a central database for immediate analysis. Testing of the QA samples can be done at any time, avoiding set test events. Conclusion Implementation of a fit-for-purpose PoCT QA for infectious disease testing removes the barriers to participation and facilitates the monitoring of testing over time. Any deficiencies in testing can be detected and addressed rapidly, ensuring that accurate test results are reported, and the population protected.

An open source 3D printed autosampler for capillary electrophoresis

BackgroundIn-house built capillary electrophoresis (CE) systems represent a significant share of laboratory instrumentation. In most of these instruments, sample injection is effected manually with low to moderate precision and requires skilled operators. Although few automated samplers have been previously developed, typically only one sample at a time can be injected. If a series of samples is to be analyzed, manual intervention is required. In the present work, we developed and constructed a fully automated, open source, CE autosampler, able to handle up to 14 different samples that can be used as a modular component of any in-house built CE instrument. ResultsAn inexpensive, 3D printed, open source, autosampler for CE was developed. The autosampler consists of two parts: an injection unit with carousel containing sample and electrolyte vials and a flushing unit, containing a miniature pressure/vacuum pump. The autosampler is operated by an Arduino Mega microcontroller and an Arduino code written in the laboratory. The injection sequence is entered through a keypad and LCD display by the user. The instrument can operate autonomously for extended periods of time. It was used for fully automated analysis and/or calibration of up to 14 samples with excellent injection repeatability reaching less than 2.7% RSD for peak areas. The sampler performance was tested with two independently built CE instruments, a CE system with contactless conductivity detection (C4D) and a CE system with laser induced fluorescence (LIF) detector. Significance and noveltyA novel, 3D printed, Arduino-based autosampler for CE was developed. The autosampler allows autonomous hydrodynamic injection of up to 14 different samples with fully programmable injection sequence, including capillary flushing and high voltage and data acquisition control. It provides the missing instrumental sampling setup for laboratory made CE instruments. It can be simply constructed based on the open-source blueprints in any laboratory and be a useful and time-saving add-on to any modular CE instrument.