A double antibody radioimmunoassay was developed for apolipoprotein A-II (apo A-II), one of the two major apoproteins of human high density lipoproteins (HDL). Apo A-II contains two identical polypeptide chains linked by a disulfide bond. A specific antiserum was raised in sheep. Tracer apo A-II was radiolabeled with 125I by the Bolton-Hunter technique. Reduction and carboxymethylation of apo A...

A new separation procedure based on the double-antibody technique has been adapted to the CENTRIA System. This procedure is universally applicable and lends itself to easy adaptation to commercial RIA kits in which liquid reagents are used. This second antibody is covalently linked to agarose (Sepharose) and the lyophilized powder is subsequently tableted for easy use on the instrument. The tec...

Employing an enzyme-linked immunosorbent assay (ELISA) technique the serum antibodies against native (double stranded) and denatured (single stranded) deoxyribonucleic acid (DNA) have been measured in various disease groups and a group of blood donor sera. The ELISA method has been compared with a radioimmunoassay method using native (double stranded) DNA is substrate antigen and a latex-fixati...