It's common to see multiple bands even when using affinity-purified antibody. This doesn't mean that there's a problem with the antibody’s specificity. Rather, this typically occurs for the following reasons: The native protein shows a different molecular weight than previously predicted. The antibody recognizes either cleaved fragments of the native protein at lower molecular weights, or post-translational modification or aggregated dimers/trimers of the native protein at higher molecular weights. The anti-peptide antibody recognizes a homologous protein in the sample that shares one or more epitopes with the peptide sequence. Unknown protein in lysate sample non-specifically binds to primary antibody or secondary antibody.
Articles in this section
- I want to develop two phospho-specific pAbs, each one of them against one phospho-site. However, these two phosphorylated sites locate very close. Is it possible to get two specific pAbs that only recognize one phospho-site with no reaction to the other?
- Will Genscript ship some samples for test before final delivery?
- Why there is no affinity purification service for mouse pAb package?
- Why there is an extra cys in the antigen sequence you designed for me? Is it necessary to conjugate the peptide to a carrier protein and why?
- Why there is no immune-affinity purification option in mAb purification?
- Why is the antibody yield so much higher for the protein A-purified package verses the other purification methods?
- Why do you need to do KLH conjugation for my antigen? What carrier protein should I choose for conjugation?
- Why do I order test bleed?
- Why am I seeing multiple or unexpected bands on a Western with my affinity purified antibody?
- Which end of the peptide “C” should be added to for KLH conjugation?