to check protein expression - (Aug/31/2006 )

I've transfected a gene cloned with GFP in human fibroblasts cell line & i want to have stable cell lines.The vector which i've used is a mammalian vector.I want to know if by any method i can check the expression of my protein just after transfection so that i don't have to wait for stable cell lines to form.

You could try RT PCR and/or western.

You can have a look at the cells using a fluorescence mucroscope: GFP gives you a green signal that you should be able to see

u will grow ur transfected cells in antibiotic media for selection, so this should give some idea.

and as dnafactory suggested, GFP fluorescence can confirm this.

suggested methods are only suitable in most cases after several hours mostly at least 8h, then cells may begin to express your GFP-tagged protein; transfection efficiency before is only detectable if you have labeled your transfection DNA with e.g. a fluorescent marker; then you can directly follow with a fluorescence microscope transfection efficiency (expression efficiency is a different thing and detectable with FM for GFP or Western)