My antibody isn’t binding to the Quantum Simply Cellular kit I just received. Can you help?
A first step is to confirm the host species of the primary antibody, as the most common reason for a complete lack of binding is antibody mismatch. We sometimes see clients mistakenly use the target species (of cells) when selecting the QSC kit, when in fact the host species of the primary antibody must be matched to the kit. As an example, the anti-human IgG QSC kit is intended for use with human antibodies, not, (e.g.) mouse anti-human antibodies for the analysis of human cells.
Another possibility, particularly for human antibodies, is that a chimeric or recombinant antibody (e.g. humanized mouse Ab) is being used. While this renders the Fc region humanized, sometimes these methods result in a slight change within the Fc region, which causes recognition issues for our QSC kit. It’s difficult for us to anticipate when this will occur, as it’s essentially antibody specific.
A final option may be that a F(ab)’ fragment, rather than whole antibody, is being used. If the antibody doesn’t have an intact Fc region, QSC beads won’t be able to bind it—specifically, QSC kits are coated with Fc-specific IgG.