Immediately following collection, thoroughly mix sample by gently inverting 5 times
Gold serum separator (SST) tube
Refrigerated (preferred) - 7 days
Frozen - 14 days
Ambient - NO
Enzyme-linked immunosorbent assay (ELISA)
Negative: <20 U/mL
Weak positive: 20 - 30 U/mL
Srong positive: >30 U/mL