Plain red top or SST tube.
Onsite [NJH]: Transport to lab within 1 hour.
Offsite: Separate serum from cells within 2 hours by centrifuge and aliquot into a labeled polypropylene or similar plastic tube.
Preferred volume: 1 mL serum
Minimum volume: 0.1 mL serum
Offsite: Frozen. Send serum Priority Overnight via FedEx and in a well insulated container on dry ice.
Stability after cell separation:
8 hours at room temperature
24 hours refrigerated at 2-8°C
>24 hours frozen at -20°C
FerroZine (Iron, serum)