Brief overview of sample collection procedures.
Whole blood for DNA isolation
Whole blood for DNA isolation is collected into Vacutainer (or analogous) 4 ml EDTA tubes. Collected blood is stored at -70oC in 800 ul aliquots in 1.5-2.0 ml sterile screw-cap tubes.
Collected blood may be frozen in collection tube with subsequent thawing and splitting into 800 ul aliquots.
Blood for serum preparation is collected into two 4 ml Vacuette (or analogous) tubes with clot activator and separator. After incubation for 20-25 min tubes are centrifuged, serum is pooled into a fresh (15 ml) sterile tube. Collected serum should be immediately split into 220 ul aliquots in sterile 0.5 or 1.5 ml screw-cap tubes and stored at -70oC avoiding thawing (this makes serum suitable for analysis of the majority of cytokines, growth factors etc).
Hair sample collection
Ten to fifteen hairs with hair follicles are asked to be collected for genetic research in case it is impossible to implement blood/serum collection and storage. Collected hair samples are stored at room temperature in usual paper envelops which makes this type of biosample collection being the most simple and inexpensive, although having restricted research capacity. Our experiments demonstrated that after 3 months of storage, hair follicles perform equally well in PCR when compared with freshly collected samples. Nonetheless, occasional control of sample integrity and suitability of being used a s a template in PCR will be performed for each remote location where this type of biosamples is collected. This is reasoned by potential effect of variations in storage conditions and extended (longer than 3 months) storage time requirement.