Hi kalsoom, their is no such optimized co-ip word exists in this world. Depending on your proteins, cells used, tag specificity, it can be optimized only through trial-error by oneself. You have to follow a standard protocol (you can get from various sources on internet) and adjust.

As you are doing a 'co-ip' plasmids should be transfected together for seeing interaction. Best wishes!

thank you sharmin

Hi Kalsoom, I agree with Sharmin there is no perfect protocol for CO-IP; however, you can check the link below to get an idea how it works. Regard to transfection, are both your target proteins exogenous? if yes, you need to do co-transfection, otherwise, you need to do the exogenous one only. Good luck