Mix well to avoid clotting. Avoid air bubbles. Immediately send to lab on ice. No needle on syringe.
Specimens must be collected in air-tight, heparinized (to a maximum of 500 USP units of heparin per 1 mL of blood) plastic syringes (Marquest TM Gaslyte ® sampler for pH, blood gas, and metabolic analysis),   available through the Central Hospital Supply Section.  These syringes are especially designed for blood gas measurements (heparinized, plastic and equipped with a tight-fitting plastic cap).  Expel any air bubbles from the syringe before sealing with a plastic cap. To keep the the specimen dry, seal the specimen in one plastic bag and put into a second plastic bag containing ice. DO NOT WRITE on specimen label with pen than has water-soluble ink. Syringes with needles are unacceptable. Specimens collected in any other device or not properly capped will not be accepted by the Chemistry Service.

Methemoglobin  percent  (SI: Mass fr = 0.01 x percent)
Performed at National Institutes of Health, Bethesda MD
Effective 19Feb03 – present:
Normal   <2

>10%