Lab 22 – Mold and Microscope
Slide Mount Instructions (go)
How to do a Gram’s Stain Test (go)
Stain Types
- Iodine is one of the more commonly available stains and is used to identify starch in a variety of samples. It will stain carbohydrates in plants and animal specimens brown or blue-black.
- Glycogen will show as red.
- Methylene Blue is an alkaline stain useful in identifying acidic cell nuclei and DNA in animal, bacteria or blood samples. It’s also useful in aquariums to prevent the spread of fungal infections in fish.
- Eosin Y is an acidic stain which stains pink for alkaline cells (cytoplasm, for example). It colors red for blood cells, cytoplasm and cell membranes. Eosin’s most important medical uses are in blood and bone-marrow testing, including the PAP smear.
- Gram’s Stain is one of the most frequently used processes in identifying bacteria – used daily in hospitals. It is a primary test that quickly and cost effectively divides bacteria into one of two types: Gram positive or Gram negative.