In this communication a safe and simple molecular diagnosis strategy was described, which can be applied for the identification of pathogens or oncogenes in clinical studies. In Southern or Northern analysis, we demonstrated the feasibility to exchange labeling probes from non-radioactive to radioactive or vice versa in a single membrane simply by stripping. We chose non-radioactive labeling because it is safe and easy to operate, but when the sensitivity is insufficient, it can be replaced by radioactive labeling. Our data show that radioactive or non-radioactive labeling is exchangeable in a single membrane and the sensitivity was comparable by either method under optimal conditions. The clinical implication is that for general hybridization starts with non-radioactive labeling, radioactive labeling is not needed unless the signals cannot be detected by non-radioactive labeling. Moreover, one membrane can be labeled repeatedly by different probes.