1-SST/1mL serum. Place specimen in the refrigerator for 30 minutes after collection. Centrifuge the specimen as soon as possitle after complete clot formation, ensuring that the barrier gel completely separates serum from cells.
Room Temp 4 days; Refrigerated 14 days
Evaluate homocystinuria. Predictor of risk for ischemic stroke and myocardial infarction. Homocystine is elevated in patients with cobalamin and/or folate deficiency, and is more sensitive than serum cobalamin and serum folate concentrations in diagnosing these vitamin deficiencies.