Collection/Processing Instructions

• Centrifugation and refrigerated/frozen storage must occur within 24 hours of collection for either sample type.      
• EDTA plasma samples may be centrifuged immediately after collection.      
• If serum is inadvertently collected (see note below), complete clot formation should take place before centrifugation.       
• After centrifugation, physically separate plasma/serum from the red cells and send aliquot for analysis.        
• Specimens must be free of particulate matter including fibrin.              

Note: Serum can only be used for initial HIV testing, it cannot be used for Mayo HVDIP confirmation             testing of REACTIVE samples.

• Specimens are stable for 24 hours at room temperature, this includes pre- & post- centrifugation time, separated or unseparated from red cells.        
• Store plasma/serum specimens at 2-8^oC if not tested within 24 hours of collection.  Separated specimens are stable for 14 days at 2-8^oC.        
• For longer storage, plasma/serum may be frozen for 8 months at -20^oC or colder. Samples may undergo up to 5 freeze/thaw cycles.        
• Frozen samples must be completely thawed, thoroughly mixed, and centrifuged before analysis.        
• For U-have testing, specimens are stable in primary tubes up to 14 days at 2-8^oC (this includes plasma stored on packed red cells, serum stored on the clot, and specimens processed and stored in gel barrier blood collection tubes).              

If REACTIVE, Mayo Medical Labs will require an additional 1 mL of EDTA plasma.