Sep 21, 2017




Clinical Hub,Tools & Resources,UWHC Lab Test Directory,Chemistry


Homocysteine (XHCYCD) Chemistry Lab Test

Name: Homocysteine

Test Name: Homocysteine

Health Link Test Code: XHCYCD

LIS Test Code: HCY

CPT Code(s): 83090

Methodology: Chemiluminescent Immunoassay

Clinical Information:

Assist in diagnosis and treatment of patients suspected of having hyperhomocysteinemia and homocystinuria.

Days Performed: Daily, 24 hours.

In-Lab Turnaround Time: 4 hours.

Stat In-Lab Turnaround Time: Not available stat.

Specimen: Blood

Collection Container: Lavender top

Collection Instructions:

Immediately refrigerate blood tube or place on cold-pack after collection.

Collection Volume: 4 mL

Pediatric Collection Volume: 0.5 mL

Stability Ambient:

6 hours on ice

Stability Refridgerated:

14 days

Stability Frozen:

1 year

Sample Analyzed: Plasma

Testing Volume: 1 mL

Pediatric Testing Volume: 0.25 mL

Specimen Processing:

Centrifuge immediately and transfer cell-free plasma to plastic vial within 30 minutes of collection.

Specimen Transport:

Transport specimen to the laboratory. Transport with coolant pack if coming from clinic location.



Age umol/L
2 months-10 years

0.0 - 8.3

11 - 15 years

0.0 - 10.3

16 - 17 years

0.0 - 11.3

18 years and up

0.0 - 15.4


Interpretation Type: Reference Interval

Test Limitations:

S-adenosyl-methionine is an antidepressant whose molecular form is similar to S-adenosyl-homocysteine. Therapeutic levels of this drug may interfere with this assay.


Patients taking methotrexate, carbamazepine, phenytoin, nitrous oxide, anticonvulsants and 6-azauridine triacetate can falsely elevate HCY levels.


Results may be affected if patient has developed heterophillic antibodies due to exposure to animal based protein products.