Mycoplasma is a genus of bacteria that do not have a cell wa

Mycoplasma is a genus of bacteria that do not have a cell wall. Would the nigrosin penetrate the bacteria? Why or why not?

Solution

Answer:

Mycoplasma lack a cell wall around their cell membrane. Since the surface of most bacterial cells including mycoplasma is negatively charged, the cell surface repels the nigrosin stain.Nigrosin is an acidic stain and is used as a negative stain. The glass of the slide will stain, but mycoplasma cells will not.