Differential: They are called differential stains because they differentiate organisms. Gram stain and acid fasting are the two differential stains. By far, the gram stain is the most widely used stain clinically. The gram stain differential between – and + and gives you clues on empiric therapy.
Protein-Based Stains. These are caused by such substances as baby food and formula, cream- or cheese-based foods, eggs, feces and urine. For fresh protein stains on washable fabrics, cold water is sometimes all you'll need to remove them. Don't use hot water, because it can cook the proteins, causing the spot to coagulate between the fibers in the fabric.
Types There can be intentional stains (such as wood stains or paint ),  indicative stains (such as food coloring or adding a substance to make bacteria visible under a microscope ),  natural stains (such as rust on iron or a patina on bronze ),  and accidental stains such as ketchup on a shirt.
How to Remove Every Type of Carpet Stain | This Old House
Aug 03, 2017· chromophore is the functional group of a dye that give colour to the stain. benzene ring and chromophore is collectively known as chromogen. auxochrome is the group that gives ionic property to the stain. Types of stains. Based on the nature of chromogen, there are three types of stain. 1. Acidic stain (Anionic stain) 2. Basic stain (Cationic stain)