Quality Control Reagents Research Articles

Evaluation of the diagnostic performance of an immunochromatographic test for Chlamydia trachomatis

ObjectivesTo evaluate the diagnostic performance of different brands of immunochromatographic test (ICT) reagents for Chlamydia trachomatis using homogenized samples to provide a reference for reagent quality control. MethodsEight commercially available ICT reagents were evaluated, of which three used the latex method and five used the colloidal gold method. Analytical performance evaluation using a pure culture broth of C. trachomatis, as well as clinical application validation using cervical epithelial cell samples acquired from the research subjects, were conducted. The concentration of C. trachomatis was quantified using a nucleic acid amplification test. ResultsThe limit of detection (LOD) of different ICT reagents in the analytical performance evaluation varied from 9.5 × 103 to 1 × 105 IFU/mL, and only one reagent met the LOD specified in the manufacturer's instructions. Likewise, only one reagent in the clinical application validation achieved the analytical LOD, four reagents were 2.1–4.2-fold of the analytical LODs, and three reagents failed to detect positive results in clinical samples. ConclusionsThe diagnostic performance of different methods and different brands of ICT reagents in clinical practice was different from the manufacturer's instructions and the results of laboratory evaluation. The diagnostic performance of reagents should be evaluated before they are actually used in clinical practice.

A human papillomavirus whole genome plasmid repository: A resource for HPV DNA quality control reagents.

Well characterized reference reagents are useful for assay validation, proficiency/competency assessment, daily run controls, and to improve inter-laboratory comparisons. Synthetic human papillomavirus (HPV) DNA fragments and plasmid clones are available, but synthetic fragments include limited segments of the HPV genome and many HPV plasmids have interrupted coding regions or contain partial genomes. As a result, they are not compatible with all HPV DNA detection and typing assays. To address this need, we are establishing an HPV plasmid repository of HPV clones containing the whole genome of each type with no interruptions in coding regions. To date, HPV plasmid clones for 16 HPV types, (including all vaccine types and 14 types in clinical assays: HPV6, 11, 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66 and 68) have been constructed using a Gibson assembly method and validated by sequencing and the Novaplex HPV typing assay. The newly constructed HPV whole genome plasmids can serve as a quality control reagent resource for HPV DNA assays and are available for public health and research laboratories.

Microplastics are overestimated due to poor quality control of reagents

Microplastics are widely distributed in the environment and pose potential ecological risks, increasing to be one of the most important environmental pollutants. However, when assessing the characteristics of microplastic contamination in environmental samples, inadequate quality control measures for the working solutions may introduce additional microplastic contamination and lead to an overestimation of microplastic abundance in the samples. In this study, we evaluated the microplastic contamination characteristics in commonly used flotation and digestion reagents to assess errors caused by microplastics in the reagents. The results showed that the abundance of microplastics in the reagents ranged from 0.8 to 43.4 items/g, with the abundance of microplastics in flotation reagents being lower than that in digestion reagents. The shapes of the detected microplastics included particles, fibers, and fragments, and their size and outline were generally small, with most being below 100 µm. The most common types of polymers detected were polyethylene and polypropylene. In order to improve the universality and readability of the results, the detected microplastic abundances were converted into the actual application concentration of the working fluid. It was found that the potential contamination of microplastics in untreated flotation solutions ranged from 1.5 to 30.8 items/mL, while in digestion solutions ranged from 0.1 to 2.3 items/mL. Our study emphasizes the need for quality control measures, such as suction filtration, when evaluating microplastics in environmental samples or conducting chemical and biological tests related to microplastics.

Cycle Threshold (Ct) Values of SARS-CoV-2 Detected with the GeneXpert® System and a Mutation Associated with Different Target Gene Failure

SARS-CoV-2 nucleic acid detection tests enable rapid virus detection; however, it is challenging to identify genotypes to comprehend the local epidemiology and infection routes in real-time qRT-PCR. At the end of June 2022, our hospital experienced an in-hospital cluster of COVID-19. When examined using the GeneXpert® System, the cycle threshold (Ct) value of the N2 region of the nucleocapsid gene of SARS-CoV-2 was approximately 10 cycles higher than that of the envelope gene. Sanger sequencing revealed a G29179T mutation in the primer and probe binding sites. A review of past test results revealed differences in Ct values in 21 of 345 SARS-CoV-2-positive patients, of which 17 cases were cluster-related and 4 were not. Including these 21 cases, 36 cases in total were selected for whole-genome sequencing (WGS). The viral genomes in the cluster-related cases were identified as BA.2.10, and those in the non-cluster cases were closely related and classified as being downstream of BA.2.10 and other lineages. Although WGS can provide comprehensive information, its use is limited in various laboratory settings. A measurement platform reporting and comparing Ct values of different target genes can improve test accuracy, enhance our understanding of infection spread, and be applied to the quality control of reagents.

Heamatological Parameters in Type 2 Diabetic Patients Attending Igbinedion University Teaching Hospital Okada, Edo State, Nigeria

Diabetes is a group of metabolic diseases in which there are high blood sugar levels over a prolonged period, and if untreated could lead to complications. This study, carried out at the Igbinedion university teaching hospital Okada to ascertain some hematological parameters, using 69 known diabetes patients who enrolled as an Out-patient in the General Out- Patient Department and 69 non- diabetes apparently healthy individuals as control. Thirty- nine of these diabetic individuals were female, while thirty were male individuals. For the non- diabetic individuals, thirty- seven were female, and thirty-two were male representing 53.6% and 46.4% respectively. Ethical approval from the institution was sought prior to commencement of study and quality control of reagents was strictly maintained. Five millilitres of whole blood was collected into an Ethylene Diamine Tetra-Acetic acid (EDTA) anticoagulated bottle, and haematological parameters including PCV, HB, WBC, RBC,MCV, MCH, MCHC and platelet count were conducted for all individuals. Result obtained for Diabetic individuals showed a mean value of 34.63, 11.24, 4.41, 7.20 and 204.27 for PCV, Hb, RBC, WBC and platelets counts respectively, while for non-diabetic individuals, a mean value of 35.04, 10.09, 3.99, 7.07 and 262.56 respectively.Hb concentration and RBC count were statistically significant (p < 0.05). The Red cell indices, MCV and MCHC, were statistically significant. This study showed a statistically significant variation in some hematological parameters of diabetic patients compared to control group .Low platelet count and alteration to red cell morphology as indicated in values of MCV and MCHC among diabetic patients are indicators of thrombotic potential. Hence, routine screening of hematological parameters should be considered for proper management of diabetic patients.

A Stable Dried Tube Specimen for Quality Assurance and Training Programs for HIV Rapid Test for Recent Infection.

The HIV epidemic is still one of the world's most serious public health challenges, affecting about 38 million people worldwide, especially in sub-Saharan African and Southeast Asian countries. In recent years, tests have been developed to discriminate recent from long-term infection in HIV-infected populations, and these tools can help identify new outbreaks and networks of transmission and target prevention and treatment plans. New rapid tests for recent infection are being deployed in point-of-care settings; however, quality assurance programs need to be implemented to ensure consistency and reliability of the results. We have developed a dried tube specimen (DTS) stabilized with disaccharide trehalose as a quality control reagent for rapid recency testing that can be stored unrefrigerated prior to reconstitution at temperatures up to 37°C for up to 12 weeks. Analysis of 10 trehalose-stabilized DTSs showed that they maintained the same recency classification in all of the samples stored at 4°C and 37°C up to 12 weeks and at 56°C for 2 weeks, while the DTSs prepared without trehalose changed their classification from long-term to recent or recent to negative after storage at 37°C for 12 weeks. Development of DTS quality control reagents will facilitate proficiency and training programs, particularly in settings without cold chain capability in field environments. IMPORTANCE Implementation of stabilized dried tube specimens (DTSs) for quality control and training would facilitate HIV recency programs, especially in point-of-care settings without cold chain availability. This study shows that addition of the disaccharide trehalose to DTSs prior to drying the samples increased stability of the samples across a range of temperatures. This finding provides an affordable way to increase the availability of these key reagents for quality control in resource-constrained settings.

Importancia de los cultivos celulares. Optimización de un ensayo para evaluar el impacto biológico del cannabidiol (CBD)

Primary cell cultures and cell lines are part of the fundamental tools for the evaluation of the efficacy and cytotoxicity of drugs, protein expression, vaccine production, evaluation of the pathogen-host relationship, among other versatile applications. Cellular study models are used to simulate dental, periodontal, and craniofacial diseases. However, the optimization and standardization can result in multiple errors that can lead to inappropriate interpretations of the results obtained in drug evaluation. This article has detailed the basic aspects of cell cultures, reagent quality control measures and good practices, the most frequent mistakes committed when culturing cells and the applicable prevention methods to reduce the risk of error. Likewise, a pilot study of the biological impact of cannabidiol (CBD) in culture with human stem cells (hDPSC) is detailed, highlighting it’s potential therapeutic effect in dentistry.

A study of quality assessment in SARS-CoV-2 pathogen nucleic acid amplification tests performance; from the results of external quality assessment survey of clinical laboratories in the Tokyo Metropolitan Government external quality assessment program in 2020

IntroductionThe Tokyo Metropolitan Government (TMG) conducted an external quality assessment (EQA) survey of pathogen nucleic acid amplification tests (NAATs) as a TMG EQA program for SARS-CoV-2 for clinical laboratories in Tokyo. MethodsWe diluted and prepared a standard product manufactured by Company A to about 2,500 copies/mL to make a positive control and distribute it with a negative control. The participants reported the use of the NAATs methods for SARS-CoV-2, the name of the real-time RT-PCR kit, the name of the detection device, the target gene(s), nucleic acid extraction kit, Threshold Cycle value in the case of RT-PCR and the Threshold time value and Differential calculation value in the case of Loop-Mediated Isothermal Amplification (LAMP) method. ResultsAs a result, 17 laboratories using fully automated equipment and 34 laboratories using the RT-PCR method reported generally appropriate results in this EQA survey. On the other hand, among the laboratories that adopted the LAMP method, there were a plurality of laboratories that judged positive samples to be negative. ConclusionThe false negative result is considered to be due to the fact that the amount of virus genome contained in the quality control reagent used this time was below the detection limit of the LAMP method combined with the rapid extraction reagent for influenza virus. On the other hand, false positive results are considered to be due to the non-specific reaction of the NAATs. The EQA program must be continued for the proper implementation of the pathogen NAATs.

METHODOLOGY FOR QUALITY CONTROL AND APPLICATION OF OILFIELD CHEMICALS

The problems and methodology of the procedure for operational field control of the application technology and oilfield chemicals are SHAPE \\* MERGEFORMAT described in the article. The methodology includes the technology of operational instrumental identification of the brand and verification of the reagent quality. The methodology is applicable at all stages of the life cycle of reagents: «laboratory research» - «field tests» - «field application» in the chemicalization of production. The methodological foundations of a new approach to operational (field) monitoring of the quality of services and oilfield reagents have been developed: control stages, a list of controlled documents, the volume and algorithm for checking permits, technology and quantitative criteria for assessing quality of oilfield reagents. Unified reporting forms have been developed, including a contractor information sheet and a feedback sheet. The unification of reporting forms is aimed at the subsequent statistical processing of an array of field reports using specified algorithms with the output of a summary on the operational quality control of reagents for any period. Current results of the project: new methodology and draft corporate standard for quality management of services and operational quality control of reagents, technology for operational instrumental identification of the brand and verification of the quality of the reagent. The prospects for the development of the technology of operational quality control have been determined, including the expansion of the field of applicability of the technology to reagents used in chemical treatment of bottomhole zones of wells, hydraulic fracturing, methods of increasing oil recovery, as well as the involvement of equipment and instrumentation measuring the composition of reagents for the incoming control procedure. Pilot field application of the project results is planned at Bashneft PJSOC. Further, the technology will be adapted for implementation in the Production Companies of Rosneft PJSC.

An evaluation of inkjet printed amino acid fingerprint test targets for ninhydrin process monitoring − and some observations

Ninhydrin was implemented as the primary police method of developing latent fingermarks on paper, cardboard and some other porous surfaces from the late 1960s. Some researchers have used individual amino acids, or mixtures of amino acids, as a method of testing the effectiveness of reagent formulations. It was not however known whether simple mixtures of amino acids could effectively emulate latent fingermarks in reactions with reagents such as ninhydrin. The first part of this study compared the effects of ninhydrin fingermark treatments used internationally in various police laboratories on test targets created by inkjet printing graduated concentrations of a representative mixture of amino acids in a series of blocks on paper. Variations in intensity of development were observed between laboratories which used various formulations and heat and humidity post treatment protocols. In a further trial in 2015 several participants in the International Fingerprint Research Group (IFRG) meeting processed test targets in their own laboratories and submitted them for measurement. Again, variation in developed intensity was observed. The depletion of the activity of ninhydrin solutions during use was also investigated in early evaluations of the test targets. An established fingerprint laboratory then processed a number of samples from a batch of targets to examine batch consistency. This was followed by designing a new test target which enabled comparisons between the developed intensity of printed test target blocks alongside depletion series of split, natural donor fingermarks. A panel of 20 donors provided depletion fingermarks and four ninhydrin formulations and treatment protocols were used. The developed test target blocks were scanned, intensity of development measured, and the results compared with the fingermark development which was evaluated by three assessors using two types of scale. Good correlation between the intensity of the developed test targets and latent fingermark quality and intensity scores was observed with the four ninhydrin treatment protocols, including some which used deliberately downgraded ninhydrin concentrations. This type of evaluation was carried out a second time to investigate modified heat and humidity protocols. The use of such test targets for routine reagent quality control and process verification would appear to be far more accurate and reliable than the use of small numbers of donor fingermarks. It is not clear why the different ninhydrin formulations investigated in the latter part of the work have very different optimum post treatment heating regimes.

Developing Quality Programs for Cell-Free DNA (cfDNA) Extraction from Peripheral Blood.

Cell-free DNA (cfDNA) analysis using peripheral blood represents an exciting, minimally invasive technology for cancer diagnosis and monitoring. The reliability of testing is dependent on the accuracy and sensitivity of specific molecular analyses to detect tumor-associated genomic variants and on the quantity and quality of cfDNA available for testing. Specific guidelines for standardization and design of appropriate quality programs focused specifically on cfDNA isolation are lacking, as are standardized quality control reagents. This report describes and illustrates quality control and quality assurance processes, supported by generation of in-house quality control material, to ensure the reliability of the preanalytical phase of cfDNA analysis. We have developed a robust quality program to support high-volume automated cfDNA extraction from peripheral blood by implementing processes and procedures designed to monitor the adequacy of specimen collection, specimen stability, efficiency of cfDNA extraction, and cfDNA quality.

Applications of Recombinant Monoclonal Antibodies against Filarial Antigen Proteins.

This study investigated the applications of recombinant monoclonal antibodies (rmAbs) produced against two recombinant filarial proteins of diagnostic value. Ab5B and Ab3A were produced against recombinant BmSXP, and Ab4 and Ab4-fragment crystallizable (Fc) against recombinant BmR1. Ab5B and Ab4-Fc were found to be useful as quality control (QC) reagents for two commercial rapid test kits, such as Brugia RapidTM and BLF Rapid® (Reszon Diagnostics International Sdn. Bhd., 47600 Subang Jaya, Selangor, Malaysia), respectively. The two rmAbs reacted positively with the corresponding recombinant proteins lined on the nitrocellulose strips of the cassette tests, thus may replace or reduce the need for patient serum samples as positive controls for QC of the commercial kits. They were also successfully conjugated to gold nanoparticles and reacted positively with the test lines containing the corresponding recombinant proteins when directly applied to the cassette tests. The gold-conjugated reagents can be used to confirm the antigenicity of test lines after the storage of the rapid tests for a prolonged period or under unfavorable conditions. Furthermore, Ab5B and Ab3A were shown to be able to capture the target recombinant proteins through immunoaffinity purification, enabling their use for applications that need very highly purified proteins. In conclusion, this study demonstrated several potential uses of rmAb proteins produced against recombinant filarial proteins.

Fluorescent amplification for next generation sequencing (FA-NGS) library preparation

BackgroundNext generation sequencing (NGS) has become a universal practice in modern molecular biology. As the throughput of sequencing experiments increases, the preparation of conventional multiplexed libraries becomes more labor intensive. Conventional library preparation typically requires quality control (QC) testing for individual libraries such as amplification success evaluation and quantification, none of which occur until the end of the library preparation process.ResultsIn this study, we address the need for a more streamlined high-throughput NGS workflow by tethering real-time quantitative PCR (qPCR) to conventional workflows to save time and implement single tube and single reagent QC. We modified two distinct library preparation workflows by replacing PCR and quantification with qPCR using SYBR Green I. qPCR enabled individual library quantification for pooling in a single tube without the need for additional reagents. Additionally, a melting curve analysis was implemented as an intermediate QC test to confirm successful amplification. Sequencing analysis showed comparable percent reads for each indexed library, demonstrating that pooling calculations based on qPCR allow for an even representation of sequencing reads. To aid the modified workflow, a software toolkit was developed and used to generate pooling instructions and analyze qPCR and melting curve data.ConclusionsWe successfully applied fluorescent amplification for next generation sequencing (FA-NGS) library preparation to both plasmids and bacterial genomes. As a result of using qPCR for quantification and proceeding directly to library pooling, the modified library preparation workflow has fewer overall steps. Therefore, we speculate that the FA-NGS workflow has less risk of user error. The melting curve analysis provides the necessary QC test to identify and troubleshoot library failures prior to sequencing. While this study demonstrates the value of FA-NGS for plasmid or gDNA libraries, we speculate that its versatility could lead to successful application across other library types.

Bacillus Calmette–Guérin strains with defined resistance mutations: a new tool for tuberculosis laboratory quality control

ObjectiveLaboratory quality control (QC) is essential to assess the reliability of tuberculosis diagnostic testing. To provide safe QC reagents for the detection of drug-resistant Mycobacterium tuberculosis, we generated antibiotic-resistant mycobacterial strains of attenuated virulence (M. bovis bacillus Calmette–Guérin (BCG)). MethodsSeven mono-resistant BCG strains were developed by introducing resistance-conferring mutations into wild-type BCG strains. Mutations were confirmed by dideoxynucleotide sequencing. Phenotypic resistance was quantified by microbroth dilution to determine the MIC90. The capacity of two commercial tests (GeneXpert TB/RIF and Genotype MTBDRplus) to detect resistance-conferring mutations was evaluated independently. ResultsOur panel included BCG strains with mutations in rpoB (S450L, I491F), katG (deletion at AA428), gyrA (D94G), rpsL (K43R) and Rv0678c (S63R). These mutations translated respectively into phenotypic resistance to rifampin (MIC ≥8 mg/L), isoniazid (MIC ≥8 mg/L), moxifloxacin (MIC 4 mg/L) and streptomycin (MIC ≥8 mg/L); the Rv0678c mutant showed decreased susceptibility to both clofazimine (MIC 4 mg/L) and bedaqualine (MIC 1 mg/L). GeneXpert (Cepheid) and Genotype MTBDRplus (Hain Lifesciences) both called the rpoB S450L strain rifampin-resistant and the I491F mutant rifampin-susceptible, as expected based on single nucleotide polymorphism positions. Likewise, MTBDRplus called the novel katG deletion mutant isoniazid susceptible despite phenotypic resistance. ConclusionBCG strains engineered to be mono-resistant to anti-tuberculosis drugs can be used as safe QC reagents for tuberculosis diagnostics and drug susceptibility testing.

Analytical and clinical performance of newly developed immunoassay for detecting thyroid-stimulating immunoglobulin, the Immulite TSI assay

Graves’ disease (GD) is caused by autoantibodies against the thyrotropin receptor (TRAb), and among the three types of TRAbs, only the stimulating type (TSI) is known to be associated with GD. In this study, we evaluated the analytical performance of a new fully automated chemiluminescent TSI immunoassay, namely, the Immulite TSI assay, and compared the diagnostic efficacy of the assay with the Elecsys Anti-TSH receptor (TSHR) assay. Precision was evaluated using two levels of quality control reagents, and linearity was evaluated across the expected analytical measurement range (0.18–37.35 IU/L) at five levels using clinical samples. A comparative evaluation between the two assays was performed using 187 clinical samples, and the concordance of qualitative results was also assessed. The repeatability and total imprecision (% coefficient of variation) of the Immulite TSI assay were 3.19% and 3.46% at 0.93 IU/L, and 3.76% and 5.42% at 19.3 IU/L, respectively. The linearity of this assay ranged from 0.16 to 6.17 IU/L. A high degree of correlation was observed between quantitative values from each assay (correlation coefficient = 0.819). Moderate agreement between methods was observed with an overall qualitative agreement of 93.0%. Among 13 cases with discordant qualitative results, the Immulite TSI assay generated more favorable results consistent with clinical diagnoses of patients than the Elecsys Anti-TSHR assay. The Immulite TSI assay showed reliable analytical performance and good correlation with the Elecsys Anti-TSHR assay and we expect this method will be helpful for clinicians to evaluate patients with hyperthyroidism.

Utility of reference materials for Zika Virus nucleic acid testing

The emergence of Zika virus (ZIKV) in the Americas has resulted in increased nucleic acid amplification testing (NAT) of clinical samples and blood donations. New molecular diagnostic assays have been developed resulting in a corollary requirement for ZIKV reference material. To address this we have produced and calibrated two African lineage ZIKV reference materials: a highly concentrated secondary standard (NIBSC: 16/110) and a lower concentration external quality control (QC) reagent (NIBSC: 16/124) and compared their performance in three ZIKV NAT assays in relation with the First International Standard (IS) for Zika Virus NAT assays (PEI: 11468/16). In summary the African lineage ZIKV reference materials were detected by all three assays. The ZIKV lineage did not affect the performance of the secondary standard. The external QC reagent (16/124) was detected by all three assays highlighting its suitability for use as a low positive control to monitor assay performance on a regular basis. The relative potency of 16/110 to the IS was 5.49E+06IU/mL (95% CI: 1.46E+06–2.06E+07) and 16/124 to 16/110 was 8.36E+03 (95% CI: 7.83E+03–8.92E+03). The global availability of African lineage ZIKV reference materials will facilitate standardization of ZIKV molecular diagnostic assays between and within laboratories whilst preserving the IS.

Abstract 1664: Comparison of RNA sequencing data generated from formalin-fixed, paraffin-embedded (FFPE) papillary thyroid carcinoma samples using different library preparation methods

Abstract Comparison of RNA sequencing data generated from formalin-fixed, paraffin-embedded (FFPE) papillary thyroid carcinoma samples using different library preparation methods. Julie Dragon, Ramiro Barrantes, Jessica Hoffman, and Scott Tighe. Genomics research requires a significant sample size to provide robust biological signal, leaving researchers clamoring for access to large sample sets. As this research continues to expand into the clinical arena, the demand to sequence RNA from banked tissue samples, such as formalin-fixed paraffin-embedded blocks, is unavoidable. Readily available, these samples represent a wealth of both patients and disease variation. However, recovering DNA and RNA from such samples can be challenging depending on age of the sample block and fixture protocols, which influence nucleic acid degradation and ultimately our ability to synthesize RNA-Seq libraries. To fulfill the need for increased recovery of quality reads, several manufacturers have developed solutions to address these challenges, including FFPE-specific extraction kits, as well as library synthesis and quality control reagents. In this study, we analyzed the quality and outcome of RNA-Seq data generated from RNA from two library synthesis kits applied to FFPE-derived human thyroid tumors with storage times from 4-12 years. The data processing pipeline included adaptor and poor quality base trimming (trimommatic), removal of rRNA reads (sortMeRNA), genomic alignment to hg19 (HiSat2), and read distribution and alignment quality assessment (RNASeqQC) (Adiconis and Levin, 2013). Differential expression was evaluated using DESeq2 (Love et al, 2014). Results indicated that of the reagents tested, it is possible to improve capture of the usable RNA data, and biological signal, with improved control of rRNA depletion and read duplication with newly developed library preparation kits specifically designed for FFPE samples. Moreover, our analysis illustrates some features of the tested synthesis kits that enable one to perform better for FFPE samples with highly varying quality, and quality metrics to consider when evaluating FFPE samples for sequencing. Citation Format: Julie Dragon, Ramiro Barrantes, Jessica Hoffman, Scott Tighe. Comparison of RNA sequencing data generated from formalin-fixed, paraffin-embedded (FFPE) papillary thyroid carcinoma samples using different library preparation methods [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1664.

P256 Optomizing the capabilities of HistoTrac as an HLA laboratory quality management tool

Aim HistoTrac (HT) provides some quality management (QM) tools such as equipment and instrument maintenance, proficiency testing, tracking patient tests from order to report, and sample and patient auditing but does not provide a built-in module for quality control (QC), compiling turnaround time (TAT) data, and laboratory logs. We optimized capabilities of HT and Microsoft Excel to create an effective QM system. Methods The following steps were taken to optimize the tools and modules provided by HT and Excel to build an effective quality system.1. Software programs used: HistoTrac (SystemLink) and Microsoft Excel2. Reagent QC: Logged, completed, and tracked as patient/sample tests3. TAT items and quality metrics: Entered, scheduled, assigned, and tracked as equipment items4. Pending list for real-time test tracking: Test data is exported with the Ad Hoc Query module, due dates are calculated using formulas and color coded using conditional formatting, distributed to staff via email. Results Tracking QC, TATs, quality metrics and laboratory log review in HT eliminated paper logs, which provided a quick and painless recall of data during inspection. Distributing the attached color coded pending list, kept the staff on top of tests approaching TAT. The attached QM dashboard that was created in Excel provides monthly, quarterly, and annual HLA lab performance, Conclusions By optimizing tools provided in the HT software and utilizing Excel table functions, we were able to create an effective means of monitoring quality metrics. We are continuing to monitor the data and processes and implement updates as necessary. Download : Download high-res image (603KB) Download : Download full-size image Download : Download high-res image (241KB) Download : Download full-size image

Recombinant human G6PD for quality control and quality assurance of novel point-of-care diagnostics for G6PD deficiency.

BackgroundA large gap for the support of point-of-care testing is the availability of reagents to support quality control (QC) of diagnostic assays along the supply chain from the manufacturer to the end user. While reagents and systems exist to support QC of laboratory screening tests for glucose-6-phosphate dehydrogenase (G6PD) deficiency, they are not configured appropriately to support point-of-care testing. The feasibility of using lyophilized recombinant human G6PD as a QC reagent in novel point-of-care tests for G6PD deficiency is demonstrated.MethodsHuman recombinant G6PD (r-G6PD) was expressed in Escherichia coli and purified. Aliquots were stored at -80°C. Prior to lyophilization, aliquots were thawed, and three concentrations of r-G6PD (representing normal, intermediate, and deficient clinical G6PD levels) were prepared and mixed with a protective formulation, which protects the enzyme activity against degradation from denaturation during the lyophilization process. Following lyophilization, individual single-use tubes of lyophilized r-G6PD were placed in individual packs with desiccants and stored at five temperatures for one year. An enzyme assay for G6PD activity was used to ascertain the stability of r-G6PD activity while stored at different temperatures.ResultsLyophilized r-G6PD is stable and can be used as a control indicator. Results presented here show that G6PD activity is stable for at least 365 days when stored at -80°C, 4°C, 30°C, and 45°C. When stored at 55°C, enzyme activity was found to be stable only through day 28.ConclusionsLyophilized r-G6PD enzyme is stable and can be used as a control for point-of-care tests for G6PD deficiency.

Theory and practice of clinical pharmacodynamics in oncology drug development

The clinical development of molecularly targeted cancer therapies is enhanced by proof of mechanism of action as well as proof of concept, which relate molecular pharmacodynamics to efficacy via changes in cancer cell biology and physiology resulting from drug action on its intended target. Here, we present an introduction to the field of clinical pharmacodynamics, its medical and laboratory aspects, and its practical incorporation into clinical trials. We also describe key success factors that are useful for judging the quality of clinical pharmacodynamic studies, including biopsy quality and suitability, specimen handling, assay fitness-for-purpose, and reagent quality control. This introduction provides not only context for the following articles in this issue, but also an appreciation of the role of well-conducted clinical pharmacodynamic studies in oncology drug development.