| A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # |
Homocysteine
Test CodeHCYS
CPT Codes
83090
Preferred Specimen
1 mL serum
Minimum Volume
0.5 mL
Other Acceptable Specimens
Plasma collected in: EDTA (lavender-top), or sodium heparin (green-top) tube
Instructions
Red-top tubes: Place the specimen in a refrigerator or ice bath for 30 minutes after collection. Centrifuge the specimen as soon as possible after complete clot formation has taken place.
Barrier gel separator tubes: Place the specimen in a refrigerator for 30 minutes after collection. Centrifuge the specimen as soon as possible after complete clot formation has taken place. Do not place barrier tubes in an ice bath as freezing may prevent the barrier gel from adequately separating serum from cells.
EDTA or heparin tubes: Place the specimen in a refrigerator or ice bath until the specimen can be centrifuged. Centrifuge the specimen as soon as possible and transfer the plasma to a plastic screw-capped vial.
(Royal blue-top) serum tube and (royal blue-top) sodium heparin tubes are acceptable containers. Instruction for collecting blood in (royal blue-top) serum tubes is similar to red-top or SS tubes or sodium heparin tubes.
Barrier gel separator tubes: Place the specimen in a refrigerator for 30 minutes after collection. Centrifuge the specimen as soon as possible after complete clot formation has taken place. Do not place barrier tubes in an ice bath as freezing may prevent the barrier gel from adequately separating serum from cells.
EDTA or heparin tubes: Place the specimen in a refrigerator or ice bath until the specimen can be centrifuged. Centrifuge the specimen as soon as possible and transfer the plasma to a plastic screw-capped vial.
(Royal blue-top) serum tube and (royal blue-top) sodium heparin tubes are acceptable containers. Instruction for collecting blood in (royal blue-top) serum tubes is similar to red-top or SS tubes or sodium heparin tubes.
Transport Container
Plastic screw-cap vial
Transport Temperature
Refrigerated (cold packs)
Specimen Stability
Room temperature: 4 days
Refrigerated: 14 days
Frozen: 6 months
Refrigerated: 14 days
Frozen: 6 months
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Gross hemolysis • Unseparated serum or plasma • Whole blood specimens • Grossly lipemic
Methodology
Enzymatic
Setup Schedule
Set up: Mon-Fri night; Report available: Next day
Reference Range
| Male | <11.4 umol/L |
| Female | <10.4 umol/L |
Clinical Significance
An elevated concentration of homocysteine is an independent risk factor for cardiovascular disease. When used in conjunction with methylmalonic acid (MMA), these tests are useful to diagnose and monitor vitamin B12 (cobalamin) and folic acid deficiency and are often useful in evaluating macrocytosis (an elevated MCV, an erythrocytic index).
Performing Laboratory
Quest Diagnostics Nichols Institute
14225 Newbrook Drive
Chantilly, VA 20153
