I'm now working on a project to investigate the effect of a drug on the delta-opioid receptors on the HEK293 cells.

I am doubtful if the wild type HEK293 cells have the delta-opioid receptors.

I had tried to search through the journals, but what information I got is that somesone has to transfect the cells with the cDNA gene in order to express the receptors on the HEK293 cells.

Can anyone tell me how to search for the information that tell if the wild type HEK293 cells have the delta-opioid receptors?

"wild type HEK293" is a bit of a nonsense concept, they're not wild type cells any more, they're a transformed cell line, transformed by sheared Ad-5 DNA.

Transformed cells loose many receptors, 293 cells do have some surface receptors though I can't see any reference to what you're interested in. Have you any reason to expect your receptor to be present in human kidney cells? (Its known in neurones), if not then there's no reason to expect it to be produced in 293 cells.

If these receptors are cell surface and not cytoplasmic (like oestrogen receptors etc) then I'd get hold of an antibody and do FACS analysis (1 hour ->result). If they are cytoplasmic then do a Western blot (2 days max.)

A quick Google for "human delta-opioid receptor" and "293" just gives papers in which the cDNA has been transfected in either transiently or stabily. I think Richard Taylor's point about 293s not being nerve cells is important.

Thanks you guys for answering me.

Indeed, I had searched through the internet and what I found is that the opioid receptors' cDNA are transfected onto the HEK293 cells for stable expression.

Now, I recognised that my project can proceed even though I don't know if the opioid receptors are expressed in the untransfected HEK293 cells (I apologize for using the term "wild type " to describe the untransfected HEK293 cells as I am not an expert and inexperienced in the research field).

Thanks for providing extra information on how to test the presence of the cellular surface receptors and the cytoplasmic receptors.