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Test Code Hcys Tot Homocysteine Quant, Total

Clinical System Name

Homocysteine Quant, Total



Sample Requirements

Specimen:Whole blood

Container(s): Lt. Green/Lithium Heparin, Dark Green/Sodium Heparin, Gold, Red

Preferred Vol: 1.0 mL

Minimum Vol: 0.5 mL


Note: Deliver to the lab - specimen must be processed within one hour of collection.


Processing Instructions

Reject due to

Spin: Y within 1 h of collection

Aliquot: Y

Temp: -20 C

Storage location: CPA Freezer, Fz5 rack


Off-site collection: Spin blood and transfer plasma to a plastic aliquot tube; freeze within one hour of collection. Keep specimen frozen during transport.


Total homocysteine will increase if blood is not spun within one hour at a rate of approximately 10% per hour (10% increase at 2 hr, 10-25% at 3 hr, 35% at 4 hr). There is no significant change if blood is kept refrigerated up to 3 hr


Specimen Type Temperature Time
Separated serum/plasma (off cells) Room temp 2 w
  Refrigerated 2 w
  Frozen 8 m


Avoid multiple freeze thaw cycles.


STAT Performed TAT
N T, F 1-4 days



Department: Chemistry

Location: Chem East

Phone Number: 206-987-2617


Reference Range


up to 1 month 0 - 7
1 month - 10 years 2 - 11
> 10 years 6 - 13.3



Method: Spectrophotometry by Vitros 4600

Analytical Volume: 0.25 mL plasma or serum

Limitations: Samples should be free of hemolysis and turbidity. Grossly icteric samples are also unsatisfactory.