Microscope Slide Stains
Since most biological structures are transparent, we need a technique to distinguish clearly the parts as we observe under the microscope. This is possible by employing some means by which contrast between different structures can be obtained. Sometimes adjusting light helps but the most common method is staining.
Stains such as methylene blue in low concentrations does not harm the tissues and so can be safely used on living materials. Such stains are called vital stains.
For making temporary slides stains such as methylene blue, idodine, aniline hydrochloride, safranin etc are used.
Given below are some common stains and their uses and the colour they show up as:
Iodine: Stains carbohydrates in plant and animal specimens brown or blue- black.Stains glycogen red.
Methylene blue: Stains acidic cell parts (like nucleus) blue. Use on animal, bacteria and blood specimens. Can be used as a substitute for Janis B green.
Eosin Y: Stains alkaline cell parts (like cytoplasm) pink. Use on plants,animals and blood. Can be used as a substitute for Congo Red and Carmine.
Safranin : Mainly used for sections of plant tissues, stains red
Toluidene blue: Stains acidic cell parts (like nucleus) dark blue. Good to show mitosis in plant cells.
Wright’s stain: Stains red blood cells pink/red.
Leishman’s stain: Stains nucleus of WBC blue and blood cells pink
Crystal Violet: Stains bacteria purple
Aceto-orcein: Biological stain for chromosomes and connective tissue.
Sudan III: Biological stain used as a lipid indicator.