Why aren't the stains like crystal violet and safranin washed away with water during simple staining?

Staining is a technique of microscopy which enhances the contrast of the microscopic image by the addition of chemicals called the stains. Simple staining is the process of staining a cell with one stain or dye. Simple stains provide a quick method of studying the cell shape, size and the arrangement in the given sample. The stain used is a basic, cationic dye which is added over the sample. A cation is a positively charged ion. The cell wall and the cytoplasm of the bacterial cells have a negative charge. So, basic stains like safranin and crystal violet get attracted to the negatively charged cells, bind to the cells and do not get washed away.

what's the question?

cells use diffusion to get substances in and out of themselves. that diffusion will occur across the cell membrane or the outer covering of the cell. because we are talking about the surface of the cell, surface area and volume are  important factors here. as a cell increases in size, its surface area and volume increase as well.  we call that the surface area to volume ratio (sa: vol).  but the catch is that  volume increases at a greater rate than surface  area. in other words, as a cell gets bigger, the sa: vol gets smaller. so a really small cell like bacteria is mostly cell membrane (surface) with very little contents (volume). a really big cell like an egg, is mostly insides with a super thin membrane. so what ends up happening is that the cell cannot efficiently diffuse all of the stuff it needs in/out to survive. therefore cell size is limited to about 100mm. so how do we make organisms bigger than 100mm? cells divide! by dividing and becoming multicellular, organisms are able to grow!   check out the diagrams i attached to see the effect of sa: vol. i hope this ! good luck!