I can't detect GPCRs in transient transfected cells via Western Blot. Cell lysates were harvested 24h after transfection. I get a really strong band with a myc antibody which detects the tagged protein and I get bands in Western Blots with tissue lysates. I recognized this problem with several GPCRs now. Do I have to conclude that my antibody does not detect the expected protein? Does anybody has an idea or suggestion?

Please check first with a positive control along with your samples. Sometimes, antibodies are not as good as you can expect. If I were you, I would first run a positive control to make sure that positive control works with that particular antibody before making any conclusion