I've got a question for everyone out there familiar with some molecular biology techniques. Could you explain western blotting? I understand the application, and I understand the procedure up to the point where you blot your protein bands onto nitrocellulose or the like. After that, it starts to get a bit hazy for me.
      I understand the use of a probe to isolate your protein of interest, and that the probe has to be attached to some other protein which is itself fluorescent or is an enzyme which cleaves a substrate into something that fluoresces/dyes so identification can occur.
      However, I don't get how someone selects the specific antibody probe, or how you image the damn thing afterwards. Are there just a few, select antibody groups that bind to some tags (6xHIS, etc.), or what? And is there a way to isolate your protein of interest if you haven't tagged its sequence with an AA marker? Like, if you didn't modify the CDS of the gene that produced that protein's mRNA so it had a polyhistidine tag, is there an antibody you could still use based on the protein's understood properties? Any help/explanation would be appreciated.