Interactions between DNA-binding fluorochromes and mucopolysaccharides in agarose-diffusion test.

Interactions between the two DNA-binding fluorochromes DAPI (4',6-diamidino-2-phenylindole) und Hoechst 33258 (2[2-(4-hydroxy-phenyl)-6-benzimidazolyl]-6-(1-methyl-4-piperazyl)-benzimidazole. 3 HCl) and certain mucopolysaccharides (heparin, sodium dextran sulphate 500, chondroitin sulphate and hyaluronic acid) were demonstrated when applying the agarose diffusion test. The resulting reactions were observed with the naked eye and appeared as precipitation lines. Saponin, a glycoside, was included in these experiments because it led to intensive fluorescent nuclear envelopes when subsequently stained with DAPI. Comparing the two fluorochromes, DAPI achieved stronger reactions with heparin and dextran sulphate 500 whereas the Hoechst fluorochrome led to broader precipitation lines with hyaluronic acid, chondroitin sulphate and saponin. Preliminary experiments also confirmed these interactions at the cellular level.