Homogeneous, Rapid Luminescent Oxygen Channeling Immunoassay (LOCITM) for Homocysteine

Abstract
Homocysteine (Hcy) is present in plasma primarily bound as disulfides with itself, Cys, and albumin (∼70%) (1)(2)(3)(4). Total homocysteine (tHcy) in serum or plasma is markedly increased in patients with cobalamin or folate deficiency (3), and decreases only when they are treated with the deficient vitamin. tHcy is therefore of clinical relevance, with reference values in fasting subjects of ∼5–15 μmol/L (1). In addition, even a moderate increase of Hcy (hyperhomocysteinemia) is a risk factor for premature cardiovascular disease (4). These disorders justify introduction of the tHcy assay in the routine clinical chemistry laboratory.