Preferred Minimum: 3.5 mL CSF Absolute Minimum: 1.5 mL CSF

Call laboratory to obtain appropriate sample collection containers. Each set consists of 5 numbered centrifuge tubes in a small plastic bag. Tube #3 contains antioxidants necessary to protect the sample from oxidation. One set of tubes is required per patient. The total CSF volume required is 3.5 mL. CSF should be collected directly from the tap needle: Collect from the first drop in to the containers in the order indicated. Fill each tube to the marked line (0.5 mL in tubes 1, 2, and 5 - 1.0 mL in tubes 3 and 4). Attach patient identifies to each tube without covering the tube number. If there is no blood contamination, place the tubes into a biohazard bag and place on ice (or dry ice if available) at the beside.

Age (years) BH4 (nmol/L) Neop (nmol/L) 0-0.2 40-105 7-65 0.2-0.5 23-98 7-65 0.5-2.0 18-58 7-65 2.0-5.0 18-50 7-65 5.0-10 9-40 7-40 10-15 9-32 8-33 Adults 10-30 8-28