Yes. Just by taking a sample of the culture medium (usually 20µl) into a fresh luminometer plate and assaying it using the ToxiLight™ Non-Destructive Cytotoxicity BioAssay Kit you can see if increased levels of Adenylate Kinase are present in your transfected cells culture supernatant indicating that they have been damaged by the transfection procedure. This would impact on your transfection efficiency values