Specimen Requirements

Submit only 1 of the following specimens:

Preferred:

Serum

Draw blood in a gold-top gel tube(s). Spin down immediately and send 1 mL of serum refrigerated.

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Note:

1. A speckled-top serum gel tube(s) or plain red-top is also acceptable.  

2. Synthesis of homocysteine by red cells continues after blood is drawn.

3. Drug therapy with S-adenosylmethionine may cause falsely elevated results.

4. These drugs have shown to interfere with some homocysteine assays:  carbamazepine, phenytoin, 6-azauridine, anthopterin, methotrexate, nitrous oxide, and other anticonvulsants.

5. Heterophile antibodies may interfere with this assay.

6. Indicate serum on request form.

7. Label specimen appropriately (serum).

Alternate:

Plasma

Draw blood in a mint green-top (heparin) gel tube(s) or a lavender-top (EDTA) tube(s). Spin down immediately and send 1 mL of heparinized or EDTA plasma refrigerated.

Note:

1. Synthesis of homocysteine by red cells continues after blood is drawn.

2. Drug therapy with S-adenosylmethionine may cause falsely elevated results.

3. These drugs have shown to interfere with some homocysteine assays:  carbamazepine, phenytoin, 6-azauridine, anthopterin, methotrexate, nitrous oxide, and other anticonvulsants.

4. Heterophile antibodies may interfere with this assay.

5. Indicate plasma on request form.

6. Label specimen appropriately (plasma).

Specimen Stability Information