Hello,

Absolutely, Co-IP can be used into the measurement of protein-protein binding research. You can used IP grade antibody for one protein to obtain this protein and other proteins binding with it. And, the MS or western bolt can be used into the detection of the proteins binding with the afore-mentioned protein.

Hello,

Yes! you can use Co-IP to measure protein-protein interactions BUT you need tight controls to eliminate any bias. Quantification you can use densitometric analysis with imageJ (an open source image processing program designed for scientific multidimensional image ).

Hi Daun,

Yes off-course you can perform co-IP for direct and indirect protein-protein interactions provided proteins are in mutual, stable interactions in cell/tissue lysate. Then use appropriate IP antibody coupled resin.

Alternatively protein microarrays can be performed for high throughput screening of p-p interaction.

Good Luck Daun!!

Do you mean to use co-IP to determine the binding affinity between A and B?

Generally it does not work unless you take very cautious approach. Simply pull down the two proteins and use western to determine the amount of A and B can give very wrong results. I will get the details when I get time

Hi Daun Jeong,

If you mean quantify or find out how much the two proteins interact with each other, it is really difficult to do with Co-IP. But, if your results are obtained when there is high salt in Lysis buffer and washing in harsh condition, the results are also stably repeated, it can be theoretically possible. Presence of negative controls is mandatory (IgG, Mock(just sepharose).

Thank you all!