Gene Expression and Transfection

Gene expression and transfection can be measured indirectly by using a reporter gene in the construct. Green Fluorescent Protein-type constructs (EGFP, etc.) or ß-galactosidase can be used to quantify populations of those cells expressing the gene/construct. Mutants of GFP are now available which may be excited at common frequencies, but emit fluorescence at different wavelengths. This allows for measurement of co-transfection, as well as simultaneous detection of gene and antibody expression. Appropriate negative (background) controls for experiments involving GFP-type constructs should be included - the control is the same cell type, using the gene insert minus the GFP-type construct.