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Test Code LAB3786 Dihydropteridine Reductase, Blood Spots

Additional Codes

Biopterin Metabolites, Urine

Clinical System Name

Dihydropteridine Reductase, Blood Spots


Biopterin; Dihydropteridine Reductase, Bld; Neopterin; PKU Cofactor; Pterins

Sample Requirements

Specimen: Whole Blood

Container(s): Dried Blood Spot Card

Preferred Vol: See Comments

Minimum Vol: 3 - 5 Full Circles of Blood


Note: Air dry filter paper samples in the dark. Place patient label on PKU card (do not need to fill out State Newborn Screen information such as birthweight or mother's name). Place in a paper envelope (no plastic bags)!

Processing Instructions

Reject due to: Insufficient blood to fill in circles; improper storage at high temperature which causes denaturation of the enzyme in the blood spots.

Spin: N

Aliquot: N

Temp: RT

Storage Location: Allow blood spots to air dry in the dark. Place dried blood spots and labels in the room temp Send Outs rack.


Specimen Type Temperature Time
  Room temp  



STAT Performed TAT
N M - F 7 d


Performing Laboratory

Children's Hospital Los Angeles (CHLA)

Department of Pathology and Laboratory Medicine

Duque Building, 2nd Floor, Room 2-290

4650 Sunset Blvd.

Los Angeles, CA 90027


Phone Number: (323) 361-2423


Department: Send Outs

Phone Number: (206) 987-2563

CPT Codes



Method: Spectrophotometric

Analytical Volume: 3 Full Circles of Whole Blood


Reference Range

1.96-7.51 units

Send Out Instructions

Reference Test Name: Dihydropteridine Reductase, Blood Spots
Reference Test Number: N/A
Instructions: Ship Monday - Thursday to Children's Hospital Los Angeles via FedEx. Saturday delivery is not acceptable.