In transition to the next generation reference materials and reference measurement procedures for apolipoprotein standardization

AbstractQuantitative PCR is the diagnostic pillar for clinical virology testing, and reference materials are necessary for accurate, comparable quantitation between clinical laboratories. Accurate quantitation of HHV-6 is important for detection of viral reactivation and inherited chromosomally integrated HHV-6 in immunocompromised patients. Reference materials in clinical virology commonly consist of laboratory-adapted viral strains that may be affected by the culture process. We performed next-generation sequencing to make relative copy number measurements at single nucleotide resolution of eight candidate HHV-6A and seven HHV-6B reference strains and DNA materials from the HHV-6 Foundation and Advanced Biotechnologies. 11 of 17 (65%) HHV6 candidate reference materials showed multiple copies of the origin of replication upstream of the U41 gene by next-generation sequencing. These large tandem repeats arose independently in culture-adapted HHV-6A and HHV-6B strains, measuring 1254 bp and 983 bp, respectively. Copy number measured between 4-10X copies relative to the rest of the genome. We also report the first interspecies recombinant HHV-6 strain with a HHV-6A GS backbone and >5.5kb region from HHV-6B Z29 from U41-U43 that covered the origin tandem repeat. Specific HHV-6A reference strains demonstrated duplication of regions at UL1/UL2, U87, and U89, as well as deletion in the U12-U24 region and U94/95 genes. HHV-6 strains derived from cord blood mononuclear cells from different labs on different continents revealed no copy number differences throughout the viral genome. These data indicate large origin tandem duplications are an adaptation of both HHV-6A and HHV-6B in culture and show interspecies recombination is possible within theBetaherpesvirinae.ImportanceAnything in science that needs to be quantitated requires a standard unit of measurement. This includes viruses, for which quantitation increasingly determines definitions of pathology and guidelines for treatment. However, the act of making standard or reference material in virology can alter its very usefulness through genomic duplications, insertions, and rearrangements. We used deep sequencing to examine candidate reference strains for HHV-6, a ubiquitous human virus that can reactivate in the immunocompromised population and is integrated into the human genome in every cell of the body for 1% of people worldwide. We found large tandem repeats in the origin of replication for both HHV-6A and HHV-6B that are selected for in culture. We also found the first interspecies recombinant between HHV-6A and HHV-6B, a phenomenon that is well-known in alphaherpesviruses but to date has not been seen in betaherpesviruses. These data critically inform HHV-6 biology and the standard selection process.

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Certified DNA Reference Materials to Compare HER2 Gene Amplification Measurements Using Next-Generation Sequencing Methods

Journal of Molecular Diagnostics ◽

10.1016/j.jmoldx.2016.05.008 ◽

2016 ◽

Vol 18 (5) ◽

pp. 753-761 ◽

Cited By ~ 12

Author(s):

Chih-Jian Lih ◽

Han Si ◽

Biswajit Das ◽

Robin D. Harrington ◽

Kneshay N. Harper ◽

...

Keyword(s):

Next Generation Sequencing ◽

Gene Amplification ◽

Reference Materials ◽

Next Generation ◽

Her2 Gene ◽

Her2 Gene Amplification ◽

Generation Sequencing

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Development of primary reference measurement procedure and reference materials for mass fraction of crude fat (oil content) in oilseeds and other products on their base

Reference materials ◽

10.20915/2687-0886-2020-16-3-37-51 ◽

2021 ◽

Vol 16 (3) ◽

pp. 37-51

Author(s):

A. S. Sergeeva ◽

E. G. Parfenova ◽

O. S. Golynets

Keyword(s):

Reference Materials ◽

Mass Fraction ◽

Oil Content ◽

Measurement Procedure ◽

Reference Measurement ◽

Reference Measurement Procedure ◽

Primary Reference

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Development of food industry metrological assurance complex

Reference materials ◽

10.20915/2687-0886-2021-17-1-21-33 ◽

2021 ◽

Vol 17 (1) ◽

pp. 21-33

Author(s):

A. S. Sergeeva ◽

N. L. Vostrikova ◽

M. Yu. Medvedevskikh

Keyword(s):

Reference Materials ◽

Mass Fraction ◽

Food Industry ◽

Nutritional Supplement ◽

Metrological Assurance ◽

Reference Measurement ◽

Primary Reference ◽

Certified Value ◽

Egg Powder ◽

Food Staples

The paper considers the contribution of experts from the Laboratory of Metrology of Moisture Measurement and Reference Materials to the improvement of the food industry metrological assurance system. The information on the results of the development of forty types of reference materials (RM) for the composition of various nutrition, food staples and nutritional supplement in the period 2008-2020 is generalized. The development of each new RM type included preparation of the material, research for its stability and homogeneity, and determination of certified value with the appliance of State primary (GET 173) and secondary (GVET 176-1) standards, as well as primary reference measurement procedures and conducting the interlaboratory experiment for checking the applicability of the RM. The creation in 2008 of GET 173 was accompanied by the development of RMs for the composition of grains and dry milk product. The approval in 2010 of GVET 176-1 allowed to add in the RM the certified value for the mass fraction of nitrogen (protein). As a result of successful participation in comparisons, UNIIM got 6 items of calibration and measurement capabilities on measurements of mass fraction of nitrogen in glycine, milk powder, grain, egg powder, cereal and feed-stuff in the BIPM database. 35 types of RM for the composition of dairy and meat products, egg powder, infant food, oil and starch products together with the development of primary reference measurement procedures for measurement of fat, crude fat, ash and carbohydrates mass fraction were created between 2016 and 2019. Moreover, the RM for the composition of nutritional supplement (glycine, melamine, cystine) and dairy products for metrological assurance of IR-analysers as well as RM for the composition of reconstituted milk were developed for the control of measurement results by the enzyme-linked immunosorbent assay (ELISA). Developed RM were systemized on fields of the appliance of Technical regulations of Customs Union and the sectors of the international food triangle model. These RMs allow providing the measurement uniformity of the identification indicators and the nutritional value of food products and food staples.

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