Why doesn't a negative stain colorize the cells in the smear?

It is impossible for a negative stain to colorize the cells in the smear because the chromogen of the negative stain carries a negative charge and is repelled as a result of the negative charge present on the surface of the cell. In this light, the stain can only colorize the background, thus permitting visibility of the capsule and the cell.

Explanation:

nucleic acid molecules are incredibly complex, containing the code that guarantees the four different nucleotide units comprise dna, the nucleic acid of interest to the genealogist. and one of four nitrogen-containing molecules called nucleotides