Hi Elias, Not sure if you've looked at this option, but Pierce sells a polyHis tag detection kit that is not based on an antibody, but instead is a "nickel-activated" derivative of HRP. Has worked quite well for us in the past.
Brian Mark On 2013-03-15, at 12:36 PM, Elias Fernandez <efern...@utk.edu<mailto:efern...@utk.edu>> wrote: Dear All, would you be able to recommend a primary anti-His6 Ab for western blotting? Thus far, the ones we’ve used are not very specific to the N-terminal hexahistidines and we pick up lots of background. Also, there’s one (others?) from Sigma that is conjugated to HRP, but costs ~$650. Thanks! Elias