Enzyme-linked immunosorbent assay blocking

An ELISA (enzyme-linked immunosorbent assay) allows for rapid screening and quantification of the presence of an antigen in a sample (Fig. 5-28b). Proteins in a sample are adsorbed to an inert surface, usually a 96-well polystyrene plate. The surface is washed with a solution of an inexpensive nonspecific protein (often casein from nonfat dry milk powder) to block proteins introduced in subsequent steps from also adsorbing to these surfaces. The surface is then treated with a solution containing the primary antibody—an antibody against the protein of interest. Unbound antibody is washed away and the surface is treated with a solution containing antibodies against the primary antibody. These secondary antibodies have been linked to an enzyme that catalyzes a reaction that forms a colored product. After unbound secondary antibody is washed away, the substrate of the antibody-linked enzyme is added. Product formation (monitored as color intensity) is proportional to the concentration of the protein of interest in the sample. 

B36. Buyon, J. P., Winchester, R. J., Slade, S. G., Arnett, F., Copel, J., eta .. Identification of mothers at risk for congenital heart block and other neonatal lupus syndromes in their children. Comparison of enzyme-linked immunosorbent assay and immunoblot for measurement of anti-SS-A/Ro and anti-SS-B/La antibodies. Arthritis Rheum. 36, 1263—1273 (1993). 

Muromonab-CD3 is an immunosuppressive agent that blocks T-cell function, which plays a major role in graft rejection, by reacting with and blocking the T3 (CD3) molecule on the membrane of human T-cells associated with antigen recognition. Serum levels are measured with an enzyme-linked immunosorbent assay (ELISA). It is indicated... 

The antagonistic effect of all 25 candidate compounds on LFA-l/ICAM-1 binding was tested in a competition enzyme-linked immunosorbent assay (ELISA). One weakly active compound was identified that blocked the interaction with an IC50 value of 70 [xM (compound 6). This compound was identified by similarity searching. 

Competition Enzvme-Linked Immunosorbent Assay. A competition enzyme-linked immunosorbent assay (cELISA) was developed to quantify the amount of heptachlor in solution and to evaluate the ability of the antibodies to distinguish among various cyclodiene insecticides and related chemicals. Microtiter plates were coated with 0.25 ng/well hept-BSA (100 p.l/well of a 2.5 ng/mL solution of hept-BSA in distilled water was allowed to evaporate onto the bottoms of the wells at 37° C). The plates were then blocked with DB as described above. Competitors (analytical standards dissolved in methanol) were added to the DB such that the resulting solution was 50% methanol. An aliquot (200 pL) of this competitor-dilution buffer solution was added to an antigen-coated well. Then, the amount of competitor was serially diluted down the microtiter plate, so each well contained 100 iL of competitor in a 50% methanol-dilution buffer solution. Next an equal volume of dilution DB 100 ng of anti-heptachlor monoclonal antibody was added to each well. Thus, each well contained 200 )xl of a 25% methanol solution in DB, antibody and competitor. Plates were incubated for 1 h at 37° C and then processed as described above. 

Scorpion Peptides Block of selected types of voltage-dependent sodium channels Block of some types of voltage-dependent potassium channels and chloride channels Enzyme-linked immunosorbent assay 0.9-5 ngmr ... 

Aucubin (15) isolated from the leaves of Aucuba japonica exhibited cytotoxic effect against cancer A-549 cells by blocking the cell cycle progression in the G(0)/G( 1) phase and inducing apoptosis. An enzyme-linked immunosorbent assay (ELISA) showed that the G(0)/G(1) phase arrest was possibly due to p53-mediated induction of p21 [143]. 

An enzyme-linked immunosorbent assay (ELISA) was performed as described previously. Briefly, each well of a 96-well microtiter plate was coated with 100 pi of the indicated concentration of sample in PBS, and incubated for 2 hr. The wells were washed three times with PBS containing 0.05% Tween 20 (washing buffer), then blocked with 0.5% gelatin in PBS for 1 hr. After washing 3 times, the wells were incubated for 1 hr with 100 pi of the primary antibody including monoclonal anti-CML antibody (2G11 1 pg/ml), monoclonal anti-CEL antibody (CEL-SP 5 pg/ml) and monoclonal anti-GA-pyridine... 

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