Anti-STAT1 抗体 (ab31369)

Thank you for your patience.


The antibody ab31369 detects both alpha and beta forms of STAT1 when it is not phosphorylated at Y701. We believe that your treatment is increasing the expression of total STAT1 as well as the phosphorylated form.

Ab30645 detects the phosphorylation of Y701 whether or not the protein is phosphorylated at S727.

Please let me know if you need any additional information or assistance.

Thank you for your emails and for your patience while I've looked into these questions.

I've heard back from the lab regarding the specificity of ab31369. The antibody should detect both the alpha and beta forms, thoughwe haven't specifically tested whether it reacts with the phosphorylated protein too. There might be some reactivity with the phosphoprotein, but we would expect it to be weaker than reactivity with the non-phosphorylated protein. Based on our conversation last week and the images you sent, it looks like the antibody is reacting quite strongly with the phosphoprotein. The lab might be running some tests to determine this, and I'll keep you posted on anything else that we find out. I'll also need to check whether the antibody could detect STAT1 cleaved at residue 694, as I don't have the full immunogen seequence in my notes.

Ab30645 is specific for STAT1 phosphorylated at Y701, and I would expect it to react with protein phosphorylated at both Y701 and S727. Some phospho-specific antibodies show weak cross-reactivity for other phospho-proteins, so it is possible that ab30645 would weakly cross-react with protein only phosphorylated at S727. I'm not sure that this has been specifically tested by the lab, but I'll check with them and get back to shortly with that information.

Regarding the images, based on molecular weights I would expect the higher band to be the alpha isoform phosphorylated at both Y701 and S727, while the lower bands would be either the beta isoform (phosphorylated or not) or alpha isoform only phosphorylated at Y701. Phosphorylations eachtend to add some weight to the protein. I think further studies might need to be done in order to know this for sure, but that seems to be the most likely explanation. There are too many possible post-translational statesat similar molecular weights in order to know for sure what each band represents based on band size.

For ab11909, I may not be understanding the question as intended, but the full-length inactive ATF6 protein is cleaved by proteases during ER stress, so I would expect this form of the protein if the cells are under this type of stress. The full-length ATF6 most likely isn't completely lost, butthe cleaved form could certainly be more abundant in the sample and the inactive ATF6 at undetectable levels. It is also possible for proteases in the samples to cleave the protein during protein isolation/sample preparation but this would generally result in several lower molecular weight bands on the Western blot. If the samples are not treated with enough protease inhibitors (or the right mix of protease inhibitors) or were not kept on ice during preparation, it is possible for this to occur. If the samples were treated correctly, and the cells were under ER stress, than I expectthat specific proteases just cleaved the protein to yield the active form. Please let me know if I misunderstood the question or if there is more information that you're seeking.

I hope this information will be useful, but please let me know if you have further questions or if there is anything else that we can do for you. I'll be back in touch once I have more information from the lab about the STAT1 antibodies.

Thank you for calling Abcam earlier today.

I am sorry about the problems you have been having with ab31369 in western blotting. The antibody is covered under our Abpromise for six months and is guaranteed to work in western blot on human samples (both tissue and cell lysate). Since you are seeing no signal with this antibody, then I would be very happy to send a replacement. A few possible alternatives are:

https://www.abcam.com/STAT1-antibody-ab2415.html
https://www.abcam.com/STAT1-antibody-ab47425.html



If you can please provide me with the Abcam order number for ab31369, and also let me know which antibody you would like to receive as a replacement, I will be happy to have it sent to you as soon as possible.

Please let me know if there is anything else I can help you with.

I am sorry that this antibody did not perform as stated on the datasheet. If payment has already been made on the original order and you wish to receive a refund, please ask your purchasing department to contact our accounting department so that we may gather the correct information needed for the refund. To avoid confusion, please ensure your accounts department is aware of how the credit note is being used. Our accounting department can be contacted by email at us.credits@abcam.com or by telephone using the information at the Contact Us link in the top right corner of our website. Please refer to the credit note ID in any correspondence with our accounting department. The credit note ID is for your reference only and does not automatically guarantee the credit. I hope this experience will not prevent you from purchasing other products from us in the future. Our Scientific Support team is always at your service, should you require further expert advice.