Reference Materials For Testing Research Articles

StellarPGx: A Nextflow Pipeline for Calling Star Alleles in Cytochrome P450 Genes.

Bioinformatics pipelines for calling star alleles (haplotypes) in cytochrome P450 (CYP) genes are important for the implementation of precision medicine. Genotyping CYP genes using high throughput sequencing data is complicated, e.g., by being highly polymorphic, not to mention the structural variations especially in CYP2D6, CYP2A6, and CYP2B6. Genome graph-based variant detection approaches have been shown to be reliable for genotyping HLA alleles. However, their application to enhancing star allele calling in CYP genes has not been extensively explored. We present StellarPGx, a Nextflow pipeline for accurately genotyping CYP genes by combining genome graph-based variant detection, read coverage information from the original reference-based alignments, and combinatorial diplotype assignments. The implementation of StellarPGx using Nextflow facilitates its portability, reproducibility, and scalability on various user platforms. StellarPGx is currently able to genotype 12 important pharmacogenes belonging to the CYP1, 2, and 3 families. For purposes of validation, we use CYP2D6 as a model gene owing to its high degree of polymorphisms (over 130 star alleles defined to date, including complex structural variants) and clinical importance. We applied StellarPGx and three existing callers to 109 whole genome sequenced samples for which the Genetic Testing Reference Material Coordination Program (GeT-RM) has recently provided consensus truth CYP2D6 diplotypes. StellarPGx had the highest CYP2D6 diplotype concordance (99%) with GeT-RM compared with Cyrius (98%), Aldy (82%), and Stargazer (84%). This exemplifies the high accuracy of StellarPGx and highlights its importance for both research and clinical pharmacogenomics applications. The StellarPGx pipeline is open-source and available from https://github.com/SBIMB/StellarPGx.

Potential new reference materials for caloric measurements on PCM

Current applications of PCM focus on the temperature range from about − 40 °C to about + 80 °C, with the interest expanding up to about 400 °C for future applications in power plants and industry. Calorimetric measurements to determine the ability of PCM to store heat as a function of temperature are done with a variety of methods and instruments. Some of them have been developed only in the last decade, especially to allow characterization of larger samples, even encapsulated PCM with volume in the order of 100 ml and larger. Currently there are not enough reference materials for calibration and testing available to sufficiently cover the required temperature range, being suitable for the used variety of samples regarding size, as well as other requirements of the new methods and instruments. In this paper, we give an introduction, review, and recommendations for new reference materials for calibration and testing.

Characterization of Reference Materials for Spinal Muscular Atrophy Genetic Testing: A Genetic Testing Reference Materials Coordination Program Collaborative Project

Spinal muscular atrophy (SMA) is an autosomal recessive disorder predominately caused by bi-allelic loss of the SMN1 gene. Increased copies of SMN2, a low functioning nearly identical paralog, are associated with a less severe phenotype. SMA was recently recommended for inclusion in newborn screening. Clinical laboratories must accurately measure SMN1 and SMN2 copy number to identify SMA patients and carriers, and to identify individuals likely to benefit from therapeutic interventions. Having publicly available and appropriately characterized reference materials with various combinations of SMN1 and SMN2 copy number variants is critical to assure accurate SMA clinical testing. To address this need, the CDC-based Genetic Testing Reference Materials Coordination Program, in collaboration with members of the genetic testing community and the Coriell Institute for Medical Research, has characterized 15 SMA reference materials derived from publicly available cell lines. DNA samples were distributed to four volunteer testing laboratories for genotyping using three different methods. The characterized samples had zero to four copies of SMN1 and zero to five copies SMN2. The samples also contained clinically important allele combinations (eg, zero copies SMN1, three copies SMN2), and several had markers indicative of an SMA carrier. These and other reference materials characterized by the Genetic Testing Reference Materials Coordination Program are available from the Coriell Institute and are proposed to support the quality of clinical laboratory testing.

Phased Haplotype Resolution of the SLC6A4 Promoter Using Long-Read Single Molecule Real-Time (SMRT) Sequencing.

The SLC6A4 gene has been implicated in psychiatric disorder susceptibility and antidepressant response variability. The SLC6A4 promoter is defined by a variable number of homologous 20–24 bp repeats (5-HTTLPR), and long (L) and short (S) alleles are associated with higher and lower expression, respectively. However, this insertion/deletion variant is most informative when considered as a haplotype with the rs25531 and rs25532 variants. Therefore, we developed a long-read single molecule real-time (SMRT) sequencing method to interrogate the SLC6A4 promoter region. A total of 120 samples were subjected to SLC6A4 long-read SMRT sequencing, primarily selected based on available short-read sequencing data. Short-read genome sequencing from the 1000 Genomes (1KG) Project (~5X) and the Genetic Testing Reference Material Coordination Program (~45X), as well as high-depth short-read capture-based sequencing (~330X), could not identify the 5-HTTLPR short (S) allele, nor could short-read sequencing phase any identified variants. In contrast, long-read SMRT sequencing unambiguously identified the 5-HTTLPR short (S) allele (frequency of 0.467) and phased SLC6A4 promoter haplotypes. Additionally, discordant rs25531 genotypes were reviewed and determined to be short-read errors. Taken together, long-read SMRT sequencing is an innovative and robust method for phased resolution of the SLC6A4 promoter, which could enable more accurate pharmacogenetic testing for both research and clinical applications.

Comparison of commercial assays and laboratory developed tests for detection of SARS-CoV-2

The global COVID-19 pandemic has led to the rapid development of tests for detection of SARS-CoV-2. Studies are required to assess the relative performance of different assays. Here, we compared the performance of two commercial assays, the cobas® SARS-CoV-2 (Roche Diagnostics) and Xpert® Xpress SARS-CoV-2 (Cepheid®) tests, and a laboratory developed RT-PCR test adapted for use on the Hologic® Panther Fusion® (Hologic®) instrument as well as Bio-Rad and QIAGEN real-time PCR detection systems. Performance characteristics for each test were determined by testing clinical specimens and reference material. All assays detect the pan-Sarbecovirus E (envelope structural protein) gene plus a SARS-CoV-2-specific target. The limit of detection for the E gene target varied from ∼2 copies/reaction to >30 copies/reaction. Due to assay-specific differences in sample processing and nucleic acid extraction, the overall analytical sensitivity ranged from 24 copies/mL specimen to 574 copies/mL specimen. Despite these differences, there was 100 % agreement between the commercial and laboratory developed tests. No false-negative or false-positive SARS-CoV-2 results were observed and there was no cross-reactivity with common respiratory viruses, including endemic coronaviruses.

Development and Analytical Validation of a 29 Gene Clinical Pharmacogenetic Genotyping Panel: Multi‐Ethnic Allele and Copy Number Variant Detection

To develop a novel pharmacogenetic genotyping panel, a multidisciplinary team evaluated available evidence and selected 29 genes implicated in interindividual drug response variability, including 130 sequence variants and additional copy number variants (CNVs). Of the 29 genes, 11 had guidelines published by the Clinical Pharmacogenetics Implementation Consortium. Targeted genotyping and CNV interrogation were accomplished by multiplex single‐base extension using the MassARRAY platform (Agena Biosciences) and multiplex ligation‐dependent probe amplification (MRC Holland), respectively. Analytical validation of the panel was accomplished by a strategic combination of > 500 independent tests performed on 170 unique reference material DNA samples, which included sequence variant and CNV accuracy, reproducibility, and specimen (blood, saliva, and buccal swab) controls. Among the accuracy controls were 32 samples from the 1000 Genomes Project that were selected based on their enrichment of sequence variants included in the pharmacogenetic panel (VarCover.org). Coupled with publicly available samples from the Genetic Testing Reference Materials Coordination Program (GeT‐RM), accuracy validation material was available for the majority (77%) of interrogated sequence variants (100% with average allele frequencies > 0.1%), as well as additional structural alleles with unique copy number signatures (e.g., CYP2D6*5, *13, *36, *68; CYP2B6*29; and CYP2C19*36). Accuracy and reproducibility for both genotyping and copy number were > 99.9%, indicating that the optimized panel platforms were precise and robust. Importantly, multi‐ethnic allele frequencies of the interrogated variants indicate that the vast majority of the general population carries at least one of these clinically relevant pharmacogenetic variants, supporting the implementation of this panel for pharmacogenetic research and/or clinical implementation programs.

Establishment of a National Taiwan Standard and working reagent for human parvovirus B19 DNA nucleic acid amplification techniques (NAT)

Mandatory requirements for plasma pools containing a maximum concentration of human parvovirus B19 DNA will be established in Taiwan in the near future. To facilitate the implementation of the policy, a National Standard and working reagent were established for human parvovirus B19 DNA nucleic acid amplification techniques (NAT). The standards are intended to be used for the quality control of B19 NAT assays and as a quantitative reference material for B19 NAT testing. A collaborative study, including 10 laboratories from seven countries, was done in order to establish the National Standard and working reagent for B19 DNA NAT assays by calibration, in International Units (IU), against the WHO International Standard for B19 (99/800). Participants were requested to test the candidate materials and the WHO International Standard by the NAT assay in routine use in the laboratory. The mean B19 DNA content of the standards was determined by each laboratory in three independent assays and the results were analyzed statistically. Overall, a high level of agreement among results was achieved from different laboratories. Consequently, the first National Standard and working reagent for B19 DNA NAT assays with an assigned value of 1.9×10^6 IU/mL and 2.0×10^4 IU/mL, respectively, were established. The results of the stability analysis indicated that both reagents were stable for 4 weeks at 25℃, for 8 weeks at 4℃, for at least 18 months at -20°C or -80℃.

Evaluation of a proficiency test of 131I, 134Cs and 137Cs in maize powder

In 2017, JRC-Geel organised a proficiency test for 120 participants on the massic activity determination of 131I, 134Cs and 137Cs in maize powder. The proficiency test reference material was produced by spiking blank maize powder. The material was characterised for its radioactive content using γ-ray spectrometry. The z scores of the reported massic activity were acceptable in 92% of the results for 131I, and in 94% for both 134Cs and 137Cs. The ζ scores were consistent with the reference value for 66% of the results for 131I, 56% for 134Cs and 68% for 137Cs.

Graphene layer number characterization using scanning kelvin probe force microscopy

As the importance of material surfaces and interfaces for industrial applications is ever increasing, a need for accuratemeasurement of their properties and functionalities with traceability and reproducibility through unbroken chain ofmeasurements and their reference materials for proficiency testing has become very important. Carbon and its allotropeshave several industrial applications and recently graphene which is a two dimensional layered material of carbon has provento have great potential, and its characterization for layer number has become very important. A need for quantitativemeasurement apart from existing qualitative techniques is very much required for accurate determination of layer number.Under the aegis of Versailles Project on Advanced Materials and Standards (VAMAS), technical working area (TWA-2) aninternational round robin test is conducted among 13 laboratories for establishing a protocol for accurate measurement ofgraphene layer number and generating reference material. CSIR-NPL being NMI of India participated and contributed to theproject which got recognition from VAMAS for its participation. Scanning Kelvin Probe Force Microscopy (SKPFM) ofgraphene layers on Au/SiO2/Si and SiO2/Si substrates is performed and their CPD data is compared. Graphene onAu/SiO2/Si has shown consistent CPD data for different modulation voltages with least uncertainty. From the comparativeanalysis it is found that SKPFM has potential to be an international standard technique to determine graphene layer numberand can generate certified reference material.

Pharmacogenomics Clinical Annotation Tool (PharmCAT).

Pharmacogenomics (PGx) decision support and return of results is an active area of precision medicine. One challenge of implementing PGx is extracting genomic variants and assigning haplotypes in order to apply prescribing recommendations and information from the Clinical Pharmacogenetics Implementation Consortium (CPIC), the US Food and Drug Administration (FDA), the Pharmacogenomics Knowledgebase (PharmGKB), etc. Pharmacogenomics Clinical Annotation Tool (PharmCAT) (i) extracts variants specified in guidelines from a genetic data set derived from sequencing or genotyping technologies, (ii) infers haplotypes and diplotypes, and (iii) generates a report containing genotype/diplotype‐based annotations and guideline recommendations. We describe PharmCAT and a pilot validation project comparing results for 1000 Genomes Project sequences of Coriell samples with corresponding Genetic Testing Reference Materials Coordination Program (GeT‐RM) sample characterization. PharmCAT was highly concordant with the GeT‐RM data. PharmCAT is available in GitHub to evaluate, test, and report results back to the community. As precision medicine becomes more prevalent, our ability to consistently, accurately, and clearly define and report PGx annotations and prescribing recommendations is critical.

Characterizing the pharmacogenome using molecular inversion probes for targeted next-generation sequencing.

Aim: This study assesses the technical performance and cost of a targeted next-generation sequencing (NGS) multigene pharmacogenetic (PGx) test. Materials & methods: A genetic test was developed for 21 PGx genes using molecular inversion probes to generate library fragments for NGS. Performance of this test was assessed using 53 unique reference control cell lines from the Genetic Testing Reference Materials Coordination Program (GeT-RM). Results: 93.7% of variants were successfully called and the repeatability rate was 99.9%. Reference calls were available for 78.4% of diplotype calls resulting from PGx testing, and concordance for the test was 85.7%. Cost per sample was $32-$56. Conclusion: A targeted NGS assay using molecular inversion probe technology is able to characterize the pharmacogenome efficiently.

Characterization of Reference Materials for Genetic Testing of CYP2D6 Alleles: A GeT-RM Collaborative Project

Pharmacogenetic testing increasingly is available from clinical and research laboratories. However, only a limited number of quality control and other reference materials currently are available for the complex rearrangements and rare variants that occur in the CYP2D6 gene. To address this need, the Division of Laboratory Systems, CDC-based Genetic Testing Reference Material Coordination Program, in collaboration with members of the pharmacogenetic testing and research communities and the Coriell Cell Repositories (Camden, NJ), has characterized 179 DNA samples derived from Coriell cell lines. Testing included the recharacterization of 137 genomic DNAs that were genotyped in previous Genetic Testing Reference Material Coordination Program studies and 42 additional samples that had not been characterized previously. DNA samples were distributed to volunteer testing laboratories for genotyping using a variety of commercially available and laboratory-developed tests. These publicly available samples will support the quality-assurance and quality-control programs of clinical laboratories performing CYP2D6 testing.

Calling Star Alleles With Stargazer in 28 Pharmacogenes With Whole Genome Sequences.

Variation in the enzymatic activity of pharmacogenes is defined by star alleles (haplotypes) comprised of single‐nucleotide variants, small insertion‐deletions, and large structural variants. We recently developed Stargazer, a next‐generation sequencing‐based tool to call star alleles for the clinically important CYP2D6 gene. Here, we present the utility of extending Stargazer to call star alleles for 28 pharmacogenes using whole genome sequencing (WGS) data. We applied Stargazer to WGS data from 70 ethnically diverse samples from the Genetic Testing Reference Materials Coordination Program (GeT‐RM). These reference samples were extensively characterized by GeT‐RM using multiple pharmacogenetic testing assays. In all 28 genes, Stargazer recalled 100% of star alleles (N = 92) present in GeT‐RM's consensus genotypes (N = 1,559). Stargazer also detected star alleles not previously reported by GeT‐RM, including complex structural variants. Our results demonstrate that combining WGS data and Stargazer enables automated, accurate, and comprehensive genotyping of pharmacogenes in the human genome.

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.

Development of Reference Materials for Noninvasive Prenatal Aneuploidy Testing by Massively Parallel Sequencing: A Proof-of-Concept Study

Noninvasive prenatal aneuploidy testing (NIPT) represents the first large-scale clinical application of massively parallel sequencing technology. However, no NIPT reference material (RM) has yet been widely adopted, impeding the development of quality management systems and standardization. Developing an NIPT RM from a biological sample is complicated by the low concentration of cell-free DNA (cfDNA), which implies pooling specimens and frequent resampling. We tested the feasibility of using DNA from immortalized cell lines of a woman and her aneuploid offspring to spike an artificial plasma matrix. Enzymatic fragmentation of extracted DNA was optimized to achieve fragment size profiles with a mode of 150 to 200 bp, similar to biological cfDNA. This synthetic material was compared with routine biological samples from pregnant women by a targeted NIPT assay in a multiplex sequencing run on a Proton platform. Sequencing statistics were similar between artificially prepared material and routine biological samples, as well as relative chromosomal representation, and no matrix effects could be detected. Estimate of fetal fraction (FF) was within the range of expected value, and aneuploidy detection statistic (z-score) was also comparable between both types of samples. Artificial plasma spiked with DNA from cell lines of mother and offspring is a promising strategy for developing NIPT RM. This type of material would offer the advantage of a constant and stable composition, allowing for greater standardization of NIPT assays. Moreover, it preserves the parental relatedness used by targeted assay to estimate FF by identification of paternal alleles in single-nucleotide polymorphisms or other variable regions.

Development of interlaboratory comparison test samples and reference materials for the quality assurance of air composition measurements

Introduction. The article presents an approach to the development of interlaboratory comparison test samples and respective reference materials for use in the metrological assurance of measurements of hazardous substances in the ambient air. Materials and methods. Solid and liquid sorbents, as well as air filters were used in the experiments. Measurement methods comprised photometry, atomic absorption spectrometry, inductively coupled plasma atomic emission spectrometry. Results. An optimized algorithm for developing multi-purpose test samples that can be used for the metrological assurance of a large number of methods for analysing ambient air is presented. Discussion and conclusions. The described approach has been used to develop test samples for laboratory proficiency testing and respective reference materials, which can be used in the certification of procedures for analysing ambient air quality, calibration of measurement instruments, as well as in the internal and external quality control of results obtained during ambient air quality measurements.

Development of Experimental Setup for Measuring Thermal Conductivity Characteristics of Soil

Thermal conductivity displays a key role in design of engineering structures where, thermal stresses resulting from heat and temperatures are of concern. Significant efforts were made to measure the thermal conductivity of different materials. For thermal conductivity characterization of soil samples it is essential to have very flexible set-up. Hence, this paper provides details about indigenously developed experimental setup for thermal conductivity measurement. The design of this newly developed setup is based on the basic principle of steady state heat flow. This experimental setup is designed in order to measure the thermal conductivity of various materials such as soils, rocks, concrete and any type of unbonded and bonded materials. In this paper, initially the theoretical background of the measurement techniques and the principle of heat flow are described, followed by design description and working procedure. The design has been kept very simple, adjustable for varying type and size of specimens and easy to operate with excellent level of accuracy as evident from system calibration. The accuracy and precision of the newly developed setup was verified by testing reference materials of known thermal conductivity and in the test results a high correlation coefficient (R2 = 0.999) between experimental data and fitting curve was achieved.

Development of Experimental Setup for Measuring Thermal Conductivity Characteristics of Soil

Thermal conductivity displays a key role in design of engineering structures where, thermal stresses resulting from heat and temperatures are of concern. Significant efforts were made to measure the thermal conductivity of different materials. For thermal conductivity characterization of soil samples it is essential to have very flexible set-up. Hence, this paper provides details about indigenously developed experimental setup for thermal conductivity measurement. The design of this newly developed setup is based on the basic principle of steady state heat flow. This experimental setup is designed in order to measure the thermal conductivity of various materials such as soils, rocks, concrete and any type of unbonded and bonded materials. In this paper, initially the theoretical background of the measurement techniques and the principle of heat flow are described, followed by design description and working procedure. The design has been kept very simple, adjustable for varying type and size of specimens and easy to operate with excellent level of accuracy as evident from system calibration. The accuracy and precision of the newly developed setup was verified by testing reference materials of known thermal conductivity and in the test results a high correlation coefficient (R^2 = 0.999) between experimental data and fitting curve was achieved.

P060 Characterization of 108 genomic DNA reference materials for 11 HLA LOCI: A GeT-RM collaborative project

Improve availability of publicly available, renewable, and well-characterized genomic DNA reference materials to support molecular HLA typing assay development, validation and verification, quality control, and proficiency testing. The Centers for Disease Control and Prevention’s (CDC) Genetic Testing Reference Materials Coordination Program (GeT-RM) together with three clinical laboratories and the Coriell Cell Repositories characterized genomic DNA from 108 cell lines for HLA-A, B, C, DRB1, DRB3, DRB4, DRB5, DQA1, DQB1, DPA1, and DPB1. DNA was isolated by the Coriell Cell Repositories and distributed to the 3 laboratories. Methodologies used were: PCR-SSO-LABType® SSO (One Lambda, Canoga Park, CA), SSP – Olerup SSP® (Stockholm, Sweden), SBT-AlleleSEQR® HLA-SBT (Abbott Molecular, Des Plaines, IL) and NGS - HoloType HLA™ kits (Omixon Inc., Budapest, Hungary). Each of the 11 genes was tested by 2 or 3 methods. Consensus genotype was the NGS result, which provided the highest level of resolution, and was consistent with the results obtained by the parallel testing using other methods. HLA typing results using SBT, SSP, SSO and NGS were 99.95 % concordant. Of the 1905 alleles typed, only one discrepancy was observed. The discrepant result was found to be due to an error in SBT/SSO typing. Five unique novel alleles with differences in exonic regions were identified and three were submitted to the WHO Nomenclature Committee. Ambiguities persisted in 50/1905 allele calls, most due to alternative cis/trans combinations of exons 2 and 3 of DPB1 (n = 21 pairs: 42 alleles) and 8 caused by polymorphisms in a non-covered region (exon1) of the DRB1and DPB1 genes. Thirty HLA-A, 54-B, 30-C, 36-DRB1, 4-DRB3, 4-DRB4, 3-DRB5, 19-DQA1, 17-DQB1, 10-DPA1 and 29-DPB1 alleles are represented in the panel. These alleles cover a high percentage of HLA specificities present in five ancestry groups in the USA population. These genomic DNA samples are publicly available from the National Institutes of General Medical Science (NIGMS) Repository at the Coriell Cell Repositories. M. Bettinotti: 3. Speaker’s Bureau; Company/Organization; One Lambda Thermo Fisher. D. Ferriola: 7. Other (Identify); Company/Organization; Licensing proceeds of the HLA-NGS protocol by CHOP to Omixon. J.L. Duke: 7. Other (Identify); Company/Organization; receiving proceeds from the licensing of the HLA-NGS protocol by CHOP to Omixon. D. Monos: 4. Scientific/Medical Advisor; Company/Organization; Omixon. 7. Other (Identify); Company/Organization; receiving proceeds from the licensing of the HLA-NGS protocol by CHOP to Omixon.

Characterization of 108 Genomic DNA Reference Materials for 11 Human Leukocyte Antigen Loci: A GeT-RM Collaborative Project

The highly polymorphic human leukocyte antigen (HLA) genes, located in the human major histocompatibility complex, encode the class I and II antigen-presenting molecules, which are centrally involved in the immune response. HLA typing is used for several clinical applications, such as transplantation, pharmacogenetics, and diagnosis of autoimmune disease. HLA typing is highly complex because of the homology of HLA genes and pseudogenes and the extensive polymorphism in the population. The Centers for Disease Control and Prevention established the Genetic Testing Reference Materials Coordination Program (GeT-RM) in partnership with the genetics community to improve theavailability of genomic DNA reference materials necessary for quality assurance of genetic laboratory testing. The GeT-RM together with three clinical laboratories and the Coriell Cell Repositories have characterized genomic DNA obtained from a panel of 108 cell lines for all HLA classic polymorphic loci: HLA-A, B, C, DRB1, DRB3, DRB4, DRB5, DQA1, DQB1, DPA1, and DPB1. The goal was to develop a publicly available and renewable source of well-characterized genomic DNA reference materials to support molecular HLA typing assay development, validation, and verification, quality control, and proficiency testing. These genomic DNA samples are publicly available from the National Institutes of General Medical Science Repository at the Coriell Cell Repositories.