Here's why:

* Basic dyes are positively charged and bind to negatively charged structures in cells, such as nucleic acids (DNA and RNA) and some proteins.

* Acidic dyes are negatively charged and bind to positively charged structures in cells, like cytoplasm and collagen.

Carbol fuchsin's positively charged chromophore (the part of the molecule that gives it its color) is responsible for its ability to stain bacteria, specifically its cell wall. This is a classic example of how basic dyes are used in microbiology.

Let me know if you have more questions!