One-Step Competitive lmmunochromatographic Assay for Semiquantitative Determination of Lipoprotein(a) in Plasma

Numerous studies have associated high concentrations of lipoprotein(a) [Lp(a)] with atherosclerosis. We developed a rapid, one-step competitive immunochromatographic assay to measure Lp(a) in plasma. The assay is per-formed on a nitrocellulose membrane strip and the result is determined by a visual readout of rust-colored colloidal selenium. The assay is based on the principle that Lp(a) in the sample will compete with Lp(a)-coated colloidal selenium for binding to the anti-Lp(a) monoclonal anti-body immobilized on the assay strip in the format of four ladder bars. The number of capture bars that appear as a result of the formation of colloidal selenium color is proportional to the concentration of the Lp(a) protein in the samples. The strip assay semiquantitatively measures Lp(a) concentrations ranging from 0 to 180 mg/L of Lp(a