Microvolumes Of Samples Research Articles

Microvolume analysis of 226Ra by inductively coupled plasma mass spectrometry: Environmental applications to high-resolution profile of wetland soil pore waters

BackgroundThe release to the environment of natural radionuclides like 226Ra due to human activities have raised concerns about human and ecosystem exposure. 226Ra’s resemblance to calcium and involvement in biological processes accentuate the importance of understanding its geochemical behavior and migration pathways. Soil and sediment pore waters provide valuable information but have proved to be challenging to analyze, requiring to push the limits of current sample preparation and detection methods often not scaled for low concentrated microvolumes of samples. A more efficient and accurate analytical method is therefore needed to get reliable data to support hydro-geochemical modeling. ResultsWe describe here a novel comprehensive approach for accurate 226Ra quantification in pore waters of a wetland located downstream of the former Rophin uranium mine. In order to highlight the migration of 226Ra between the different soil layers, microvolumes of soil pore waters were in situ sampled up to 50 cm depth employing Diffusive Equilibrium in Thin-Films (DET) probes. The workflow included spiking DET extracts with an in-house 228Ra tracer, specific solid-phase extraction with 50 mg of AnaLig Ra-01® resin, and elution fraction calcination. This process eliminated interferences and simplify the analysis matrix. Quantification relied on isotope dilution after measurement by ICP-MS hyphenated to a desolvator module and to a microsampler (150 µL injection). The resulting 1 cm-high-resolution profile revealed unusual 226Ra enrichment with depth, signs of Ra mobility from the solid contamination source. These elements are essential for assessing 226Ra distribution coefficients across soil horizons and subsequent wetland remobilization considerations. Significance and noveltyThis first methodological advance for 226Ra constitutes a significant step to understand 226Ra behavior i.e., to quantify its activity level, fluxes inside of wetland soils or at the interface overlying waters/sediments. Its potential extension to studies involving other elements underscores its broader applicability in environmental research. The findings contribute to evidence-based decision-making for environmental protection and management, aiding in the preservation of ecological integrity and human health.

Effects of storage temperature and time on metabolite profiles measured in dried blood spots, dried blood microsamplers, and plasma

The practical advantages of capillary whole blood collection over venipuncture plasma collection for human exposome research are well known. However, before epidemiologists, clinicians, and public health researchers employ these microvolume sample collections, a rigorous evaluation of pre-analytical storage conditions is needed to develop protocols that maximize sample stability and reliability over time. Therefore, we performed a controlled experiment of dried whole blood collected on 10 μL Mitra microsamplers (DBM), 5-mm punches of whole blood from a dried blood spot (DBS), and 10 μL of plasma, and evaluated the effects of storage conditions at 4 °C, −20 °C, or −80 °C for up to 6 months on the resulting metabolite profiles measured with untargeted liquid chromatography-high resolution mass spectrometry (LC-HRMS). At −80 °C storage conditions, metabolite profiles from DBS, DBM, and plasma showed similar stability. While DBS and DBM metabolite profiles remained similarly stable at −20 °C storage, plasma profiles showed decreased stability at −20 °C compared to −80 °C storage. At refrigerated temperatures (4 °C), metabolite profiles collected on DBM were more stable than plasma or DBS, particularly for lipid classes. These results inform robust capillary blood sample storage protocols for DBM and DBS at potentially warmer temperatures than −80 °C, which may facilitate blood collections for populations outside of a clinical setting.

Development of Green and High Throughput Microplate Reader-Assisted Universal Microwell Spectrophotometric Assay for Direct Determination of Tyrosine Kinase Inhibitors in Their Pharmaceutical Formulations Irrespective the Diversity of Their Chemical Structures.

This study discusses the development and validation of a universal microwell spectrophotometric assay for TKIs, regardless of the diversity in their chemical structures. The assay depends on directly measuring the native ultraviolet light (UV) absorption of TKIs. The assay was carried out using UV-transparent 96-microwell plates and the absorbance signals were measured by a microplate reader at 230 nm, at which all TKIs had light absorption. Beer's law correlating the absorbances of TKIs with their corresponding concentrations was obeyed in the range of 2-160 µg mL-1 with excellent correlation coefficients (0.9991-0.9997). The limits of detection and limits quantitation were in the ranges of 0.56-5.21 and 1.69-15.78 µg mL-1, respectively. The proposed assay showed high precision as the values of the relative standard deviations for the intra- and inter-assay precisions did not exceed 2.03 and 2.14%, respectively. The accuracy of the assay was proven as the recovery values were in the range of 97.8-102.9% (±0.8-2.4%). The proposed assay was successfully applied to the quantitation of all TKIs in their pharmaceutical formulations (tablets) with reliable results in terms of high accuracy and precision. The assay greenness was evaluated, and the results proved that the assay fulfils the requirements of green analytical approach. The proposed assay is the first assay that can analyse all TKIs on a single assay system without chemical derivatization or modifications in the detection wavelength. In addition, the simple and simultaneous handling of a large number of samples as a batch using micro-volumes of samples gave the assay the advantage of high throughput analysis, which is a serious demand in the pharmaceutical industry.

Measurement of tigecycline in dried blood spots by LC-MS/MS and comparison tigecycline concentrations between whole blood and plasma.

An LC-MS/MS method was established to measure tigecycline in dried blood spots (DBSs). The DBS specimens obtained by applying 30 μl of blood to filter paper were extracted with hydrogen oxide and subsequently precipitated protein with perchloric acid, then the extract was directly analyzed by liquid chromatography tandem mass spectrometry. A Hypersil GOLD aQ column was utilized for separating the analytes, and detection was carried out in positive and selective reaction monitoring modes. The precursors to product ion transitions m/z 586.3 → 513.1 and m/z 586.3 → 569.2 were monitored for tigecycline, and m/z 473.2 → 456.0 and m/z 473.2 → 367.0 for 9-amino minocycline as internal standard. The validation parameters of specificity and selectivity, linearity (0.02-5μg ml-1 ), sensitivity (limit of quantification 0.02 μg ml-1 ), intra- and interday precision (within 15%) and relative error (within ±15%) were acceptable. The recoveries were from 84.65% to 90.49% and from 85.41% to 95.72% for tigecycline and internal standard, respectively, and the matrix effect was not evident to influence accuracy. The impact of hematocrit on measurement of the analyte was negligible, and after preserving at ambient temperature for 24 h and at 4°C for 1month it remained steady. The advantages of nonintrusive blood collection and micro-volume sample requirements make DBS a potent surrogate to conventional venepuncture for sampling.

Imprinted ratiometric fluorescence capillary sensor based on UiO-66-NH2 for rapid determination of sialic acid

Development of method with micro-volume reagent usage and high selectivity for rapid determination of valuable disease-related biomarkers is of great importance for disease surveillance. Herein, a novel ratiometric fluorescence capillary imprinted sensor was developed for highly selective fluorescence determination of sialic acid (SA) based on luminescent metal-organic framework (UiO-66-NH2). In this strategy, the imprinted pre-polymer with double emissions was sucked into the capillary to grow imprinted layer on the inner wall of the capillary. In presence of SA, the blue fluorescence (440 nm) served as fluorescence response signal was quenched due to the electron transfer mechanism between metal organic framework and SA while the red fluorescence (655 nm) served as the reference signal was remained. Within SA concentration linear range of 1.0 × 10−7–3.0 × 10−4 M, the ratiometric fluorescence capillary imprinted sensor was applied to detect SA in human serum and saliva samples successfully with a detection limit of 2.5 × 10−8 M. A sensitive and selective fluorescence method with micro-volume sample consumption (15 μl) for determination of SA in practical samples was established.

A near-infrared fluorescence capillary imprinted sensor for chiral recognition and sensitive detection of l-histidine

This work firstly developed a near-infrared fluorescence capillary imprinted sensor with high selectivity and sensitivity for the chiral recognition of l-histidine. The near-infrared fluorescence imprinted polymer prepared by sol-gel method using CdTe quantum dots as the near-infrared fluorescence source was self-sucked into activated capillary to form the fluorescence imprinted capillary. The fluorescence imprinted capillary sensor had higher fluorescence response efficiency. With the superior stability, reproducibility and reusability, the fluorescence capillary imprinted sensor displayed higher selectivity toward l-histidine. Under the optimal conditions, the fluorescence intensity (λex = 370 nm, λem = 695 nm) of the fluorescence capillary imprinted sensor was enhanced in proportion to l-histidine concentration ranged from 0.1 pM to 1.8 pM with a limit of detection of 0.08 pM. Spiking experiment showed that the fluorescence capillary imprinted sensor was successfully used for determination of l-histidine in human urine and serum with the recoveries of 99.6–102.7%. The near-infrared fluorescence capillary imprinted sensor possessed significantly potential for high sensitive detection of l-histidine, which realized trace-level analysis for micro-volume sample and provided promising utility for green chemical.

Automated spectrophotometric platform for the quantification of multiple nucleic acid samples

A novel automated spectrophotometric platform was developed to upgrade a conventional prototype instrument platform for commercial use. A pulsed xenon flash lamp was chosen as the light source to improve the light output and a microsampling system was employed to precisely and rapidly aspirate micro-volume sample solutions. In addition, a three-axis positioning system was devised to increase the measurement capacity. All electrical components of the developed platform were linked and controlled with an integrated system. To verify the measurement performance and automated operation, a series of experiments were carried out. Double-stranded DNA samples at seven concentrations were automatically quantified. The concentrations were estimated with high linearity (R 2 ≒ 0.9998), repeatability (relative standard deviation ≤10.3%), and accuracy (>87.5%) across the concentration range from 0.25 to 10 ng/μL. In addition, this platform can be used in many different ways by changing a few parts or a sub-system and will be most useful in laboratories that handle a large number of samples. It is expected that the developed platform will be utilized for measuring circulating cell-free DNA and for quality control of next-generation sequencing, forensic medicine, noninvasive prenatal tests, and liquid biopsies.

Влияние природы активных компонентов и модификаторов на электроаналитические свойства планарных цефалексин-селективных сенсоров

The 1st generation cefalexine-cephalosporine antibiotic is used in the treatment of various infectious diseases. Spectrophotometry, kinetic spectrophotometry, spectrofluorimetry are proposed to determination of cefalexine in medicine and biological environment. Planar screenprinted sensors allow analyzing the micro-volumes of samples, which is important for the analysis of biological objects without preliminary samplepreparation. Depending on the active material and modifiers, you can create planar sensors for the determination of different organic compounds. In this work we have studied the influence of the nature of electroactive compounds and modifiers on the electroanalytic properties of planar cefalexine-selective sensors. Associates of tetradecylammonium and dimethyldistearylammonium with complex compounds silver (1) – cefalexine (Ceas = 1–3%), polyaniline modifiers and cupric oxide nanoparticles have been used as active components, the ratio EAS: modifier is 1:1. The main electroanalytic and operational characteristics of cefalexine-selective sensors in aqueous solutions and on the background of oral fluid are determined. Advantage of tetradecylammonium in active components of cefalexine-selective sensors is shown. For cefalexine- sensors, the optimal is: linearity interval 1·10-2 – 1·10-4, response time 20–25 seconds, for unmodified: 10–15 sec, for modified in 1·10-2 M solutions of cefalexine, service life – 1 month. Modifiers approximate angular coefficients of electrode functions to theoretical values for single-charge ions, reduce response time and drift of potential, reduce the detection limit of cefalexine. Sensors are used for the determination of cephalexine in model aqueous solutions and oral fluid with added antibiotic additives, in expired cephalexine preparations.

Research progress of microextraction by packed sorbent and its application in microvolume sample extraction

微萃取技术是分析化学领域发展迅速,且已经得到广泛应用的样品前处理技术。填充吸附剂微萃取(MEPS)是一种微量固相萃取技术,使用微量的吸附剂填充于微量注射器,通过反复抽推方式使样品多次流经吸附剂以完成样品吸附萃取过程,萃取后的样品可直接用于色谱分析。典型的MEPS萃取设备包括MEPS注射器和MEPS吸附床(BIN)。MEPS优化的主要因素为MEPS处理过程的参数,包括样品流速、样品量与样品萃取循环次数,吸附剂及淋洗、洗脱溶剂的种类和体积,还需要考虑样品基质对MEPS性能的影响和样品残留和重复使用问题。MEPS中最重要的部分是吸附剂,主要有商品化的MEPS吸附剂,包括硅基的Silica、C18、C8等,碳材料的Hypercarb和聚苯乙烯聚合物类的SDVB、HDVB吸附剂等。研究用的吸附剂包括分子印迹材料、限进分子印迹材料、碳基材料、导电聚合物类材料、改性硅基材料及共价-有机骨架材料等。MEPS结合多种分析仪器已经成功应用于从不同基质中提取单一或多种分析物,所涵盖基质包括生物样品(尿液、唾液、血浆或血液)、河流水体或生活污水以及几种食品和饮料。MEPS处理复杂生物基质样品时,通常需要稀释样品、除蛋白质等预处理。MEPS具有需要样品体积小、操作快速等特点,在生物基质样品分析中有望得到更广泛的使用。在环境样品中,该技术可与现场便携仪器联用,未来将有望在现场进行快速检测,并于易分解样品等方面发挥作用。

MONITORING OF ENVIRONMENTAL OBJECTS USING ECOLOGICALLY CLEAN ELECTRODES

The review article presents the achievements of stripping voltammetry with modified environmentally friendly carbon-containing electrodes in environmental monitoring of the environment. The main objective of the research was the complete elimination of toxic mercury from the analytical procedure and its replacement with modifiers, which include bismuth, hydroxyapatite, montmorillonite, ionic liquids, chitosan, materials based on plant and animal cells, as well as their composites with graphite. The issues of development creating microchips with the use of screen printing technologies for solving problems of microtechnology and innovative technologies in the manufacture of microelectrodes that allow analysis in microvolumes of samples are considered. Examples of the use of bismuth and hydroxyapatite modified screen-printed electrodes in the analysis of heavy toxic metals in environmental objects are given. Screen-printed electrodes allow the use of portable systems for real-time analysis, and the automation of their production process makes them more versatile for routine use at low costs, which, in turn, allows their disposal use, especially in demand for non-invasive medical diagnostics.

High recovery, point‐of‐collection plasma separation from blood using electrospun polyacrylonitrile membranes

AbstractMicrovolume blood collection technologies are of intense interest in healthcare. Whereas dried blood spots collect all the blood components, the majority of clinical tests are performed on the noncellular, plasma component of blood. Thus, there is a critical need for a robust plasma‐collecting device, which can stabilize biomarkers of interest for clinical analysis. A dried plasma spot, which consists of a separation membrane for removing red blood cells (RBC) while avoiding cell lysis and an absorbing layer for collecting and stabilizing plasma biomarkers after separation may provide such a solution. We report a novel use of electrospun polyacrylonitrile membranes to achieve a very promising separation of RBCs with near‐zero retention of human albumin protein (MW: 66.5 kDa). Physicochemical qualities of the separation membranes can be further optimized through doping and refinement of electrospinning conditions. The membranes may have future potential in microvolume sample collecting applications.

Metabolic Analysis at the Nanoscale with Multi-Isotope Imaging Mass Spectrometry (MIMS).

Incorporation of a stable-isotope metabolic tracer into cells or tissue can be followed at submicron resolution by multi-isotope imaging mass spectrometry (MIMS), a form of imaging secondary ion microscopy optimized for accurate isotope ratio measurement from microvolumes of sample (as small as ∼30 nm across). In a metabolic MIMS experiment, a cell or animal is metabolically labeled with a tracer containing a stable isotope. Relative accumulation of the heavy isotope in the fixed sample is then measured as an increase over its natural abundance by MIMS. MIMS has been used to measure protein turnover in single organelles, track cellular division in vivo, visualize sphingolipid rafts on the plasma membrane, and measure dopamine incorporation into dense-core vesicles, among other biological applications. In this article, we introduce metabolic analysis using NanoSIMS by focusing on two specific applications: quantifying protein turnover in single organelles of cultured cells and tracking cell replication in mouse tissues in vivo. These examples illustrate the versatility of metabolic analysis with MIMS. © 2020 Wiley Periodicals LLC. Basic Protocol 1: Metabolic labeling for MIMS Basic Protocol 2: Embedding of samples for correlative transmission electron microscopy and MIMS with a genetically encoded reporter Alternate Protocol: Embedding of samples for correlative light microscopy and MIMS Support Protocol: Preparation of silicon wafers as sample supports for MIMS Basic Protocol 3: Analysis of MIMS data.

Electrochemical microcell based on silver solid amalgam electrode for voltammetric determination of pesticide difenzoquat

This study presents an application of a non-toxic mercury meniscus modified silver solid amalgam electrode as a reliable, user-friendly and sensitive sensor for the determination of herbicide difenzoquat as a model pollutant in micro volumes of samples. Difenzoquat gave one cathodic peak at around –1.4 V (vs. Ag/AgCl/3 mol L–1 KCl reference electrode) independent on pH (in the range 8–12). Sharp maxima greatly influenced the peak of the analyte and they were eliminated by the addition of gelatine as a surface-active compound. The optimal supporting electrolyte was found to be Britton-Robinson (BR) buffer with pH 12. Determination of the analyte in the 10 μL volume was carried out in a newly developed simple microcell with the amalgam working electrode. A procedure for fast and reliable removal of dissolved oxygen was used. Difenzoquat was therefore successfully determined by differential pulse voltammetry in BR buffer pH 12 and in model river water samples with addition of gelatine with limits of quantification 0.41 and 0.45 μmol L–1, respectively. It was proved that this sensor can be directly used for monitoring of pollutants in volumes of tens of microliters of various samples with similar parameters as the determination in larger volumes.

The factors affecting the reproducibility of micro-volume DNA mass quantification in Nanodrop 2000 spectrophotometer

The DNA mass concentration should be accurately estimated prior to various DNA manipulations and molecular analyses. However, there was no systematic report about the factors affecting the reproducibility of micro-volume DNA mass quantification. In this study, the performance of micro-volume analyzer and the factors affecting DNA quantification were studied systematically. The results revealed that the precision and accuracy of Nanodrop 2000 spectrophotometer were excellent within concentration range from 30 to 500ng/μL. The homogeneity of DNA solution had great effect on the quantification result. The concentration order for different parts of DNA solution after storage was bottom > center > upper. Furthermore, the measured results increased as delay time extended. The increased speed for smaller loading volume was faster than that for larger loading volume. In addition, the residue from the loaded sample of high concentration had a little effect on the next determination for low concentration sample. In summary, Nanodrop 2000 spectrophotometer was reliable for DNA quantification of micro-volume sample. And attention should be paid to solution homogeneity, delay time, loading sample volume and cross contamination during determination. This could be referred as guidance for micro-volume DNA quantification.

Sample shape design for a micro‐volume NMR spectroscopy

The authors examined a shape of sample on micro-volume, which is a several μL, nuclear magnetic resonance (NMR) spectroscopy in order to obtain uniformed magnetic flux density in the sample and a sharp NMR spectrum by using a conventional NMR apparatus. Firstly, they simulated the magnetic flux density distribution in spherical and cubic shaped samples and calculated NMR spectra from each shape. The simulated NMR spectra from spherical samples were sharp enough, being <0.1 ppb in a full width at half maximum (FWHM). On the other hand, the simulated NMR spectra from cubic samples were much broader than those from spherical samples. Then, they made polydimethylsiloxane sample chambers with spherical or cubic sample of several µL in volume and they evaluated NMR spectra from those micro-volume sample chambers. As a result, they obtained a sharp NMR spectrum with FWHM of 2 ppb from the sample chamber with the spherical sample, and a broad spectrum with FWHM of 220 ppb from the sample chamber with the cubic sample. These results indicate that the spherical shape is essential to obtain a shape spectrum in micro-volume NMR spectroscopy by using a conventional NMR apparatus.

Measurement uncertainty in Total Reflection X-ray Fluorescence

Total Reflection X-ray Fluorescence (TXRF) spectrometry is a multi-elemental technique using micro-volumes of sample. This work assessed the components contributing to the combined uncertainty budget associated with TXRF measurements using Cu and Fe concentrations in different spiked and natural water samples as an example. The results showed that an uncertainty estimation based solely on the count statistics of the analyte is not a realistic estimation of the overall uncertainty, since the depositional repeatability and the relative sensitivity between the analyte and the internal standard are important contributions to the uncertainty budget. The uncertainty on the instrumental repeatability and sensitivity factor could be estimated and as such, potentially relatively straightforward implemented in the TXRF instrument software. However, the depositional repeatability varied significantly from sample to sample and between elemental ratios and the controlling factors are not well understood. By a lack of theoretical prediction of the depositional repeatability, the uncertainty budget can be based on repeat measurements using different reflectors. A simple approach to estimate the uncertainty was presented. The measurement procedure implemented and the uncertainty estimation processes developed were validated from the agreement with results obtained by inductively coupled plasma — optical emission spectrometry (ICP-OES) and/or reference/calculated values.

Quantum dots encoded Au coated polystyrene bead arranged micro-channel for multiplex arrays

This paper describes a promising micro-channel multiplex immunoassay method based on the quantum dots encoded beads which requires micro-volume sample. Briefly, Au nanoparticles coated polystyrene (PS) beads were prepared and Quantum dots (QDs) were employed to encode 4 types of the PS beads by different emission wavelength QDs and various intensities. Different coding types of the beads were immobilized with different antibodies on the surface and BSA was used to block the unsatisfied sites. The antibody linked beads were then arranged in the 150µm diameter optical capillary where the specific reactions took place before the detections. Results showed that the antibody on the Au coated surface maintains the bioactivity for the immunoreactions. Using this system, the fluorescent intensity was linear with analyte concentration in the range of 1×10−7–1×10−5mg/mL (RSD<5%, 4 repeats) and the lower detection limit reached 5×10−8mg/mL. It was proved to be a promising approach for the future miniaturization analytical devices.

A novel analysis method for lactate dehydrogenase activity in serum samples based on fluorescence capillary analysis.

Based on fluorescence capillary analysis technology, a method for quantitating lactate dehydrogenase (LDH) activity in a micro-volume sample was developed. Sample and reagent consumptions were merely 2 and 16 μL per time, respectively. The optimized test conditions were as follows. The reaction reagent consisted of 0.10 M phosphate buffer (pH 6.5), 0.30 mM NADH and 1.20 mM pyruvate. NADH standard was prepared with a phosphate buffer of pH 8.0, and its linear response was controlled in 0.05 - 0.30 mM. LDH standards containing 2.0 mM PEG could exhibit long-term stability. Under the optimized conditions, a linear response for LDH from 50 to 1200 U L(-1) and a detection limit of 31 U L(-1) were obtained with good precision (RSD: 2.1 - 2.2%, n = 10) and better recovery of 96 - 105%. The method's characteristics was high sensitivity, low consumptions, simple operations, good precision and reliability, lending itself to the miniaturization of fluorophotometer which transformed into a bedside instrument in the hospital.

Reduced-gravity Environment Hardware Demonstrations of a Prototype Miniaturized Flow Cytometer and Companion Microfluidic Mixing Technology

Until recently, astronaut blood samples were collected in-flight, transported to earth on the Space Shuttle, and analyzed in terrestrial laboratories. If humans are to travel beyond low Earth orbit, a transition towards space-ready, point-of-care (POC) testing is required. Such testing needs to be comprehensive, easy to perform in a reduced-gravity environment, and unaffected by the stresses of launch and spaceflight. Countless POC devices have been developed to mimic laboratory scale counterparts, but most have narrow applications and few have demonstrable use in an in-flight, reduced-gravity environment. In fact, demonstrations of biomedical diagnostics in reduced gravity are limited altogether, making component choice and certain logistical challenges difficult to approach when seeking to test new technology. To help fill the void, we are presenting a modular method for the construction and operation of a prototype blood diagnostic device and its associated parabolic flight test rig that meet the standards for flight-testing onboard a parabolic flight, reduced-gravity aircraft. The method first focuses on rig assembly for in-flight, reduced-gravity testing of a flow cytometer and a companion microfluidic mixing chip. Components are adaptable to other designs and some custom components, such as a microvolume sample loader and the micromixer may be of particular interest. The method then shifts focus to flight preparation, by offering guidelines and suggestions to prepare for a successful flight test with regard to user training, development of a standard operating procedure (SOP), and other issues. Finally, in-flight experimental procedures specific to our demonstrations are described.

Reduced-gravity environment hardware demonstrations of a prototype miniaturized flow cytometer and companion microfluidic mixing technology.

Until recently, astronaut blood samples were collected in-flight, transported to earth on the Space Shuttle, and analyzed in terrestrial laboratories. If humans are to travel beyond low Earth orbit, a transition towards space-ready, point-of-care (POC) testing is required. Such testing needs to be comprehensive, easy to perform in a reduced-gravity environment, and unaffected by the stresses of launch and spaceflight. Countless POC devices have been developed to mimic laboratory scale counterparts, but most have narrow applications and few have demonstrable use in an in-flight, reduced-gravity environment. In fact, demonstrations of biomedical diagnostics in reduced gravity are limited altogether, making component choice and certain logistical challenges difficult to approach when seeking to test new technology. To help fill the void, we are presenting a modular method for the construction and operation of a prototype blood diagnostic device and its associated parabolic flight test rig that meet the standards for flight-testing onboard a parabolic flight, reduced-gravity aircraft. The method first focuses on rig assembly for in-flight, reduced-gravity testing of a flow cytometer and a companion microfluidic mixing chip. Components are adaptable to other designs and some custom components, such as a microvolume sample loader and the micromixer may be of particular interest. The method then shifts focus to flight preparation, by offering guidelines and suggestions to prepare for a successful flight test with regard to user training, development of a standard operating procedure (SOP), and other issues. Finally, in-flight experimental procedures specific to our demonstrations are described.