Critical Evaluation of the DNA-methyl Green Assay: Application to Some Indole Alkaloids

A DNA-methyl green colorimetric microassay for the detection of agents that interact with DNA was assessed with reference molecules (doxorubicin, ellipticine, melinonine F, dihydroflavopereirine, cis-Pt, mitomycin C, emetine or colchicine). This test showed some promise as a screening technique for substances that intercalate partly or totally into the DNA helix but it is not suitable for substances that bind covalently to DNA. An application of this test to a number of indole alkaloids was also performed. Cryptolepine, serpentine, alstonine and matadine induced a reduction of the colour of the solution, so indicating an interaction with DNA.