Question

Why acetocarmine is only used for staining of nucleic acid?

Answer 1

In cytochemistry, basic stains like acetocarmines are used to stain basic molecules, such as nucleus and chromosomes. Acetocarmine impart red colour to chromosomes during it's staining. By the use of this stain we can observe different stages of chromosomes during cell division.
To selectively stain DNA, Fuelgen reaction is used under controlled condition.