Patient should be in a fasting and resting state (should not exercise).

Grey Sodium flouride (NaFl)

Tube should be pre-chilled prior to sample collection

• Draw blood into chilled gray-top tube
• Immediately following collection, mix sample thoroughly by gently inverting 8 - 10 times to prevent clotting

1. Immediately after blood is drawn, add 2 mL of whole blood from the gray-top tube to 2 mL of 8% perchloric acid (7 mL of 70% perchloric acid diluted to 100 mL with deionized water). Perchloric acid tube   
   1. Use 1:1 blood (ie, equal parts) to 8% perchloric ratio if less blood is obtained.
2. Shake mixture vigorously for about 30 seconds.
3. Refrigerate for five minutes to ensure complete protein precipitation.
4. Centrifuge 5 to 10 minutes at approximately 1500xg.
5. Immediately transfer the CLEAR SUPERNATANT to a Transfer vial/tube with cap - 12mL (LabCorp).
   1. A second centrifugation of the supernatant may be necessary to obtain a clear protein-free solution.
6. Label the transport tube as "SUPERNATANT" and send to the laboratory.

Transfer vial/tube with cap - 12mL (LabCorp)

Ambient (preferred) - 5 days

Refrigerated - 7 days

Frozen - 7 days

Freeze/thaw cycle - stable x3

• Whole blood received
• Grey-top tube not prepared with perchloric acid

Pyruvate - lactate; spectrophotometry

0.3 - 0.7 mg/dL