I am looking for tandem affinity purification (TAP) tags that have been used in C. elegans, and I found several including LAP tag, HA-Hisx6-Myc tag and so on.
But all the tags I found include GFP or His, which I cannot use in my experiment.
Now I realize that you do not wish to use an 8xHis tag; this purification protocol relied on the HA and Myc tags. The first step was using Protein A coupled anti-HA antibody(MAb12CA5), followed by elution with 2xHA peptide. Then Protein A coupled anti-Myc antibody (MAb9E10) was used. The complex was cleaved off the beads with TEV protease. You could probably either generate a similar tag yourself and leave out the 8xHis tag, or get the vector (which I have) and use Gibson cloning to swap in a flexible linker in place of the 8xHis tag.
That said, I don’t really like the HA and Myc tags all that much. I prefer 2xFLAG tags (easier to compete off beads with peptide). FLAG-Myc could work, but leave a TEV cleavage site between the epitopes, since it is very difficult to compete Myc-tagged proteins off beads.
Another alternative that looks appealing (though I have not tried) is using Streptavidin one-step purification. You could add the 15-23 amino acid biotin acceptor peptide to your protein of interest (could add a 2xFLAG tag if you wanted a 2nd tag). The BirA biotin ligase would need to be co-expressed. This approach was used mammalian cells and transgenic mice for one-step complex purification (http://www.ncbi.nlm.nih.gov/pubmed/17093407;http://www.ncbi.nlm.nih.gov/pmc/articles/PMC164612/).