Anti-S100A9 antibody (ab75478)

Please read customer's answers: "I used different concentrations of antibody We always use proteinase inhibitor cocktail Roche Our secondary antibody is really good" Lot: GR23908 Thank you for the assistance and reply.

ANSWER:

My colleague Anja is on tour for Abcam this week and therefore I am dealing with this case. I apologize for the delay of my reply!

Thank you very much for confirming these details for us.

Looking at the previous correspondence, it appears that - although you confirmed important details - we are awaiting more information on the sample preparation in order to help us better understand the difficulties experienced. We would appreciate if your customer can confirm what conditions were used, i.e. native/denaturing/reduced. As the protein S100A9 is known to form homodimers and heterotetramers, it would be important to know how the samples had been prepared, in order to assess if the additionally observed bands represent multimers, which might be reduced with slight protocol changes.

Also, as Anja suggested I would like to recommend using 5%BSA as blocking agent since some antibodies produce better results with BSA. The previously used 1% skimmed milk might not be sufficient to block all unspecific binding of this antibody.

I also agree that the small 4kDa band observed could be unspecific binding or a degradation product running at the bottom front of the gel. As you confirmed using a freshly prepared proteinase cocktail though, it is in my opinion not really something to worry about, as it is sufficiently far away from the specific 16 kDa band and might disappear with stronger blocking conditions.

As mentioned before, running a negative control such as an un-transduced sample or an empty vector control would be advisable. This would help to determine the source of the unspecific bands.

We appreciate your understanding of our policies. Please be reassured that should the suggestions not improve the results, we will be pleased to provide a credit note, free of charge replacement or refund.

I hope this information is helpful, thank you and your customer for your cooperation. Please do not hesitate to contact us if you need any more advice or information.

Please feel free to contact us again if you have any additional questions or concerns.