Q: When we contacted you to find out more about having a custom saporin conjugation performed with our primary antibody, you recommended that we use the ATS secondary conjugate system to determine that our antibody was specific to the population we want to eliminate. We looked more at the website, and it seems that we are supposed to start with Anti-M-ZAP, Cat. #IT-30 (our primary Ab is a mouse IgM), and use the Mouse IgM-SAP, Cat. #IT-41 for control. Is this correct?
A: If your primary antibody is a mouse IgM, then you are correct that Anti-M-ZAP (Cat# IT-30) is the appropriate secondary conjugate to use. As for control conjugates, the best control would be a secondary conjugate using an IgM isotype control mixed with Anti-M-ZAP. An alternative would be to use Goat IgG-SAP (Cat# IT-19) made with normal goat IgG that mimics Anti-M-ZAP without the specific affinity for mouse IgM.
Once you determine you need a direct conjugate made between your mouse IgM primary antibody and saporin, then you would want to use the Mouse IgM-SAP (Cat# IT-41) as a control toxin just as you use your direct conjugate.