The enzymatic activity of human aldehyde dehydrogenases 1A2 and 2 (ALDH1A2 and ALDH2) is detected by Aldefluor, inhibited by diethylaminobenzaldehyde and has significant effects on cell proliferation and drug resistance

► ALDH1A2 and ALDH2 overexpression in two cell lines results in increased cell proliferation and drug resistance. ► Diethylaminobenzaldehyde inhibits both ALDH1A2 and ALDH2. ► The enzymatic activity of both isoenzymes can be detected by Aldefluor flow cytometry assay.