Test Code HOMCY 
Methodology Chemiluminescent Microparticle Immunoassay (CMIA) 
Description Useful for biochemical diagnosis of inborn errors of methionine and related cofactors (folate, vitamin B6, and vitamin B12) metabolism. This test is also useful as an independent risk factor of cardiovascular disease, an indicator of acquired folate or cobalamin deficiency, and as a contributing factor in the pathogenesis of neural tube defects. 
Specimen Draw blood in a lavender-top (EDTA) tube from a fasting patient. IMMEDIATELY spin down and IMMEDIATELY separate plasma from cells. Send 1.0 mL (minimum volume: 0.5 mL) of plasma refrigerated in a plastic screw-capped vial.

NOTE: If unable to immediately separate plasma from cells, place sample on wet ice upon collection. Sample may be maintained on wet ice for up to 6 hours prior to separation of plasma from cells. Upon separation, sample must be refrigerated.

NOTE: The following drugs may elevate levels of homocysteine: methotrexate, carbamazepine, phenytoin, nitrous oxide, anticonvulsants, and 6-azauridine triacetate, The mechanism of action of these drugs affects different parts of the metabolic pathway of homocysteine.

S-adenosyl-methionine is an antidepressant whose molecular form is similar to S-adenosyl-homocystine. 

Reference Values Adults: 0 -13.9 Ámol/L
Reference values and interpretation apply to fasting specimens only, non-fasting specimens will be rejected. 
Analytic Time 1 Day 
Day(s) Test Set Up Monday through Friday 
CPT Code(s) 83090