Question: What is the benefit of staining kidneys in bright colours?

Heather Eyre answered on 19 Jun 2013:

The dyes are picked because they stain for certain things within tissues, they just happen to be brightly coloured. But bright colours are easier to see and photograph than pale ones.

Unstained sections are really hard to look at under the microscope as you can’t tell the cells apart and there is very little contrast.

Collagen, which forms a network holding cells together, stains with a bright blue dye called aniline blue. So by using that blue stain I can tell how much collagen is in my kidney slices, too much collagen sort of clogs the whole thing up and stops the kidney working properly!

The reason many different colours are used is so that you can see lots of different structures in one slice – it makes it easier to see whats going on if you have something to compare the staining to.

The most common stain is H & E stain, which stands for Hematoxylin (stains the cell nucleus blue-purple) and Eosin (which stains the rest of the cell a pinky colour). You can really see the structure of the cells using this stain, so if there are too many cells you can see the clusters or you can see if the cells have gotten bigger than they should be.