The 17th International HLA and Immunogenetics Workshop (IHIW) organizers conducted a Pilot Study (PS) in which 13 laboratories (15 groups) participated to assess the performance of the various sequencing library preparation protocols, NGS platforms and software in use prior to the workshop. The organizers sent 50 cell lines to each of the 15 groups, scored the 15 independently generated sets of NGS HLA genotyping data, and generated "consensus" HLA genotypes for each of the 50 cell lines. Proficiency Testing (PT) was subsequently organized using four sets of 24 cell lines, selected from 48 of 50 PS cell lines, to validate the quality of NGS HLA typing data from the 34 participating IHIW laboratories. Completion of the PT program with a minimum score of 95% concordance at the HLA-A, HLA-B, HLA-C, HLA-DRB1 and HLA-DQB1 loci satisfied the requirements to submit NGS HLA typing data for the 17th IHIW projects. Together, these PS and PT efforts constituted the 17th IHIW Quality Control project.

It is demonstrated that the output optical signal of MTT test is directly proportional to the number of viable cells in the primary culture of mesenchymal cells (skin fibroblasts and mesenchymal stem cells from the bone marrow, placenta, and umbilical cord). The slope of the best curve in coordinates "cell number - optical signal" reflecting specific productivity of MTT-formazan characterizes mean dehydrogenase activity of cells and their physiological activity. It was found that in vitro dehydrogenase activity of primary cultures of mesenchymal cells increased during the first 3-5 passages and then tended to decrease. The variant of MTT method presented here can be used for standardization of cell materials.

Mesenchymal stem cells enzymatically isolated from human placenta were labeled with magnetic fluorescent microparticles (d=0.96 μ). We showed that microparticles in high doses (>10 μl stock suspension per 1 ml culture medium) significantly inhibited cell proliferation in culture. In our work we determined the optimal concentration of particles not affecting physiological properties of mesenchymal stem cells: it does not change cell proliferation, does not induce apoptosis, and does not modulate their transdifferentiation into neuronal cells. In vivo experiments showed that the chosen particles allow easy visualization of transplanted cells ex vivo on sections of different tissues.

The novel HLA‐C*02:212 allele was characterized using next generation sequencing technology.