Profile: Fidelis Research Ltd. is a human tissue procurement company. We put all efforts in expanding our network of collection sites in order to collect diverse human tissue types in different forms, including matching blood products and biospecimens. All biofluids are available as non-pooled aliquots from individual cases. Each aliquot is accompanied by detailed clinical information. Cryopreserved PBMCs are a common specimen source for studies of immunological responses to vaccines, and immunotherapies. The health and viability of cells recovered post-cryopreservation are of course critical to the success and accuracy of immunological assays performed on them.