I have been working with immunoprecipitations for a short while and I always use a control with IP extract and no antibody. What I have been hearing is that a more proper control for IPs is the use of a control IGG antibody is this correct? If so can someone explain in detail the reasoning behind this. Lets say I am incubating my extract with a proteinX antibody that is anti-mouse, and then on the western blot I probe for proteinZ that is also anti-mouse....does the control IGG need to be anti-mouse?
Would my negative control for this co-IP be (IP extract + control IGG anti mouse antibody)?
Please help. Thanks.