Idescribea simple enzyme-linked immunosorbent assay (ELISA) for the quantitation of Factor VIll-related antigen in plasma with use of commercially available peroxidase-labeled antiserum and solid-phase support. Regression analysis of 85 plasma samples analyzed by this technique (y) and by a commonly used electroimmunoassay (Anal. Biochem. 15: 45-52, 1966) (x) gave the equation y = 0.223 + 0.77x...

We have studied the roles of von Willebrand factor (vWF) and factor Vlll in arterial thrombosis in four canine phenotypes: normal (n = 6). hemophilia A (n = 1 l ) , von Willebrand disease (vWD) (n = S), and hemophilia A/vWD (n = 1). vWF activity was determined by botrocetin-induced agglutination of fixed human platelets and vWF antigen (vWF:Ag) by Laurel1 electroimmunoassay and crossed immunoel...

The physiological regulation of glutamine synthetase (GS; EC 6.3.1.2) in the axenic Prochlorococcus sp. strain PCC 9511 was studied. GS activity and antigen concentration were measured using the transferase and biosynthetic assays and the electroimmunoassay, respectively. GS activity decreased when cells were subjected to nitrogen starvation or cultured with oxidized nitrogen sources, which pro...

We used a noncompetitive enzyme-linked immunoassay to measure apolipoprotein B (apo-B) concentration in human plasma. Goat anti-lipoprotein B immunoglobulins were adsorbed to the surface of polystyrene balls. After washing, this solid-phase antibody was incubated with antigen (plasma from normal or hyperlipoproteinemic fasting subjects), washed, and then incubated with peroxidase-labeled goat a...

Four of the membrane proteins from Acholeplasma laidlawii that are soluble in the nonionic detergent Tween 20 have been purified by preparative electrophoretic techniques utilizing different supporting media. The last purification step for two of the major proteins was a preparative polyacrylamide gel electrophoresis performed in the absence of any detergent. The proteins were recovered by cont...

Recent data suggest that mutant immunoreactive forms of apolipoprotein C-II (apoC-II) can be detected in the plasma of patients with the apoC-II deficiency syndrome. We studied the possible presence of apoC-II mutants in the plasma of two patients with apoC-II deficiency by immunological means. The patients were hypertriglyceridemic, and apoC-II was undetectable in plasma as determined by radia...

The B apoprotein occurs in a wide range of plasma lipoproteins, which are heterogenous both with respect to size and to composition. Immunochemical recognition of the apoprotein is influenced by the nature of the particle in which the apoprotein is found, presumably due to the masking of the antigenic sites by lipoprotein lipid. Consequently, it is difficult to provide suitable standards for us...

A number of immunological techniques--radioimmunoassay, enzyme-linked immunosorbent assay (ELISA), electroimmunoassay, radial immunodiffusion, and a variety of immunoprecipitin assays--have been used to quantify apolipoproteins in plasma. This paper outlines their technical details and discusses their major advantages and drawbacks. The most sensitive procedures, RIAs and ELISAS, are best suite...

An improved procedure for the Laurell "rocket" technique is described. Samples were electrophoresed in an agarose gel containing anti-human albumin. The gel plates were processed, the peaks stained, and peak heights used to calculate albumin concentrations. Factors affecting precision were (a) adequate heating of agarose gel before antibody is added, (b) accurate leveling of the gel surface dur...