Development of Coded Sample Panels for Training of Rospotrebnadzor Specialistsand Validation of New Laboratory Techniques

1. Introduction: Panels of pathogen-containing control samples are necessary for training of specialists of the Russian Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing (Rospotrebnadzor), drills of rapid response teams of specialized anti-epidemic brigades, external quality control of Rospotrebnadzor laboratories by Reference Centers, method validation in laboratories, and participation of Rospotrebnadzor laboratories in proficiency testing (PT) and interlaboratory comparison tests (ICT). Objective: To prepare panels of coded samples of deoxyribonucleic acids (DNA) and complementary DNA (cDNA) of pathogens of highly contagious infectious diseases to be used for training of specialists in Rospotrebnadzor institutions and mobile units and for validation of new laboratory methods. Materials and methods: We used lyophilized samples of rhinovirus and SARS-CoV-2 cDNA and Yersinia pestis, Francisella tularensis, Vibrio cholerae, Brucella suis, and Bacillus anthracis DNA. DNA was obtained from bacterial suspensions of the above microorganisms, cDNA was derived from positive controls contained in reagent kits produced in Russia, and “negative” samples were obtained from embryonic calf serum. All samples were dehydrated with 15 % sucrose solution. Results: We developed panels of control samples to be used for PCR detection of highly contagious bacterial pathogens and the most common viruses. We also established their optimal storage time and temperature. To this end, dehydrated samples were kept at temperatures of +4 °C, +26 °C, +37 °C, and –20 °C during 30 days and tested for stability. The optimal storage times for the samples was determined to be 7 days. The samples were then assembled into panels, adhering to confidentiality principles, and sent to laboratories. Conclusion: The prepared panels of control samples can be used for training of Rospotrebnadzor specialists, including those included in mobile units, in PCR testing and validating new techniques in Rospotrebnadzor laboratories.