I'm looking for a molecular biomarker to differentiate these two cell lines, both are kidney cells but I need to check cross-contamination in cell culture.
HEK293T cells were from HEK293 cells transformed with large T antigen.
HEK293 cells were immortalized with with adenovirus. Thus 293T cell will express large T antigen and E1A (from adenovirus). ISLK cells are naturally occured tumor cell line. You can see which cells express large T antigen.