Immunoprecipitation and Chromatin Immunoprecipitation (ChIP) Assays
Antibody Solutions has documented expertise in discovery and generation of antibodies to transcription factors with utility in ChIP. For example, we generated an antibody to recombinant human His6-tagged SLUG, a zinc finger suppressor protein that binds a 221-bp silencer sequence located at 700 bp upstream of the BRCA2 gene transcription start site. The left panel of the figure below shows the utility of this antibody in Western Blotting, while the right panel presents data from a ChIP assay showing the in vivo binding of SLUG to a silencer DNA sequence in MDA-MB-231 and BT-549 cells but not in MDA-MB-468s that do not express SLUG mRNA.
Generating Clones to Transcription Factors
An antibody to the transcription factor SLUG binds to α-SLUG on Western Blots and specifically binds to the 221-bp silencer sequence located at 700 bp upstream of the BRCA2 gene transcription start site.
In a recent program for the development of antibodies directed at the STAT1 protein, we generated 35 clones positive for paraformaldehyde-fixed cells (as in ChIP) using our rapid immunization and Hybridoma Library™ approach. Only 33 percent of antibodies positive for fixed cells were positive by ELISA. In addition to demonstrating that our approach is suitable to generate clones to transcription factors, this finding illustrates the advantages of direct-to-application screening for identifying antibodies with the desired utility.