Anti-6X His tag® 抗体 [4D11] (ab5000)

The main difference between ab18184 and ab5000 is the immunogen used to produce the antibodies. ab18184 was produced against a 6X His synthetic peptide, while ab5000 was raised against a recombinant protein fused to a 6X His tag. Thus, ab18184 was originally designed to detect HHHHHH alone while ab5000 was orginally designed to detect HHHHHHGS. A reseacher tested ab5000 and submitted an abreview showing that it also recognizes the HHHHHH alone.

I can confirm that all four products, the ab5000, ab15149, ab18184 and ab81663 detect proteins, which contain either an N or C-terminal HHHHHHGS (6x) epitope tag.

Important aspects for his tag recognition are, the localisation of the tag (N- or C-terminal) and the length of the his tag, that should be identical with the antibody chosen.

Furthermore it is important to confirm that the tagged protein is expressed in transfected or transformed cells. If the recombinant protein is expressed, it should not make a difference for the detection if either a bacteria or a mammalian system was used.

However, some his tag antibodies could cross react with other proteins in the used system. For ab81663, ab15149 there may be seen some cross reactivity with extracts of insect or mammalian cells

I really wouldn't expect the antibody would cross-react with glycine, particularly as there is only a single glycine in the epitope tag. If it recognised a single glycine it'd cross react with nearly all untagged proteins as it's a very common amino acid. I can't think of any proteins that have an internal string of histidines but perhaps that is the problem?

This antibody does indeed recognise the classical 6 x His tag HHHHHH, and therefore I would fully expect it to recognise your PMAHHHHHH motif.

The immunogen of this antibody is recombinant malaria protein TRAP fused at the amino-terminal end with six his tag. It does recognize proteins which contain either an N or C-terminal HHHHHHGS epitope tag. Unfortunately, we do not know how neighbouring glycine would influence the binding of the antibody to the epitope.

We are only able to guarentee the concentration of purified antibodies, and as this antibody is ascitic fluid it does not fall into that catagory.