Sign in →

Test Code PKU COFACT PKU Cofactor Variant Screening

Important Note

This testing replaces PKU Cofactor Variant Screening at Perkin Elmer.

Additional Codes


Pterins U

Clinical System Name

PKU Cofactor Variant Screen Orderset



Dihydropteridine Reductase,Bld
Pteridine Profiling, Urine


PKU Cofactor

Sample Requirements

Specimen: Whole Blood

Container(s): Dried Blood Spot Card

Preferred Vol:See Comments

Minimum Vol: 2 - 4 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)!


Specimen: Urine

Container(s): Sterile Container (PROTECT FROM LIGHT)

Preferred Vol: 2 mL

Minimum Vol: 1 mL


Note: Protect sample from light and send to lab immediately.

Processing Instructions

Reject due to: NA, forward to Send Outs

Spin: N

Aliquot: N (Blood Spots), Y (Urine, aliquot into amber vial)

Temp: RT (Blood Spots), -20 C (Urine)

Storage location: Allow Blood Spots to air dry in the dark. Place dried Blood Spots and labels in the room temp Send Outs rack. Place light-protected urine sample in the -20 CPA freezer, Send Outs rack.


Specimen Type Temperature Time
  Room temp  



STAT Performed TAT
N M - F 0800-1700 12-15 d


Performing Laboratory

University of Illinois Medical Center

Biochemical Genetics

820 S. Wood, Rm 337 Bldg 911 CSN

Chicago, IL 60612


Phone Number: (312) 996-5326



Department: Send Outs

Phone Number: (206) 987-2563


Reference Range



Dihydropteridine Reductase, Filter Paper, Blood 1.133 ± 0.345 umol/minute/disc
Pterins Qualitative, Urine Neopterin/biopterin ratio: 0.3-3.0



Dihydropteridine Reductase, Filter Paper, Blood

Method: Enzyme assay


Pterins Qualitative, Urine

Method: High performance liquid chromatography (HPLC)




CPT Codes



Send Out Instructions


Reference Test Name:

Dihydropteridine Reductase Activity & Urine Pterins

Reference Test Number:  
Instructions: Ship Monday - Thursday to University of Illinois via FedEx. Saturday delivery is not acceptable.