重组人c-Fos蛋白(ab56280)

Thank you for contacting us.


We produce c-FOS in insect cells, so the protein may have some phosphorylation levels in some sites. We’ve tried to limit the kinase activity during the production process, including the expression stages and purification steps, but we can’t protect its phosphorylation completely. Also, we can’t test the modification levels in all of the sites, but we still think our c-FOS protein is a good substrate for most of application assays. Even you had the positive signal in the Thr232, we don’t think that site has been fully phosphorylated, and you may have used too much protein (˜80ng) to do the WB.

We would suggest that you do a dilution study (such as starts at 20ng>>>) in WB with phosphor-antibody and protein-antibody, and to see if you can get the protein amount point which shows the positive signal in protein-Ab and negative one in phosphor-Ab. You may then use the optimized protein amount to do his test

I hope this information is helpful to you. Please do not hesitate to contact us if you need any more advice or information.

Thank you for your enquiry. The MW weight of the GST tag is approximately 25kDa. The FOS protein is about 53kDa. Therefore, as seen on the WB image, a 78kDa band was detected.