What collection methods are necessary for testing plasma lactate and pyruvate concentrations?
For plasma lactate analysis, blood samples should be collected pre-exercise, post 10 minutes of exercise, and after 30 minutes of rest into sodium fluoride/potassium oxalate (grey top) tubes. The plasma for lactate analysis should be separated, frozen and shipped on dry ice. For plasma pyruvate analysis, an 8% solution of perchloric acid (PCA, Perchloric acid 60% Fisher Scientific A-228-6) or tricholoracetic acid (TCA) is needed for collection. An 8% solution is made by diluting 13.3 ml of 60% PCA or TCA to 100 ml in distilled water. This solution is stable if refrigerated for 6 months. Immediately after blood collection, add exactly 2 ml of blood to 2 ml of 8% PCA or TCA. Mix and place on ice for 10 minutes to insure complete precipitation of protein. Centrifuge, pull off the clear supernatant, and then freeze supernatant. The frozen samples should be shipped on dry ice by an overnight delivery service. Pyruvate is unstable unless plasma collected by this method.
