Irrelevant antibody

There are two types of specificity checks that may be warranted when choosing a specific peptide. The first is to demonstrate that the peptide is bound by the desired antibody and not by other, antigenically irrelevant antibodies. An example of this kind of specificity check is shown in Figure 7.3. A peptide that is immunoreactive with the 1D5 estrogen receptor (ER) mAb was covalently bound as a 1 pL spot to the center of each grid location. Various antibodies and controls were subsequently applied to the different grid locations. The bottom panel describes each of the antibodies that were applied to each grid location. The ability of the various antibodies to bind to the peptide was tested by immunohistochemistry. The presence of antibody bound to a... 

Control slides of known reactivity should be run with each set of slides immunostained. Appropriate controls should include an irrelevant antibody of the same immunoglobulin class at an equivalent concentration. 

A polyclonal antibody, which by nature cannot be monospecific, can, if its titer is very high, behave like a monospecific antibody in comparison with the low titers of irrelevant antibodies in the same serum. Thus, this method is faster and performs better than other polyclonal antibody techniques while retaining all the advantages of polyclonal antibodies. 

Solvent controls for all chemical inhibitors and preincubation controls for metabolism-dependent inhibitors must be included. Preimmune serum and ascites (or irrelevant antibodies) should be included as negative controls for antibody inhibition studies. 

Figure 1.7. Binding to mouse pulmonary artery endothelial cells of two liposome preparations functionalized with relevant antibodies (34A and 201B) (filled and open circles, respectively), functionalized with an irrelevant antibody (open squares) or uncoated liposomes (filled squares) (data from ref. (76))...

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