In a gram positive stain it is because the cell's cell wall is made up of peptioglycan
Negative staining techniques are designed to stain everything BUT the bacterial cells. This allows us to see the cells unstained and helps us observe their morphology (how the cells are shaped and how they group together). The cells have an overall negative charge on their surface, so they naturally attract positive charges. Crystal Violet carries a positive charge, so it would adhere to the surfaces of the cells thus staining the cells (which is not what you want in a negative stain!)
Methylene blue stain is used to stain plant and animal cells.
Endospore staining is a differential stain used to detect the presence and location of spores in bacterial cells.
A basic dye used in gram staining is crystal violet.
The gram stain uses a decolorizing product so it is possible to differentiate between the gram and the gram cells. Gram positive cells stain purple in color.
The causes a stain adheres to bacterial cells is the color-bearing ions (chromophores) and they might be positively charged (cationic), such as methylene blue, basic fuchsin, and crystal violet, because bacteria are negatively charged and anionic chromophores, such as eosin, will not stain bacteria because of the electrostatic repelling forces that are involved.
Negative staining techniques are designed to stain everything BUT the bacterial cells. This allows us to see the cells unstained and helps us observe their morphology (how the cells are shaped and how they group together). The cells have an overall negative charge on their surface, so they naturally attract positive charges. Crystal Violet carries a positive charge, so it would adhere to the surfaces of the cells thus staining the cells (which is not what you want in a negative stain!)
Gram positive bacterial stain purple. They do not take up the counter stain.
You absolutely do not heat fix a blood smear before staining, that is, if you are looking at the blood cells. For bacteria, why wouldn't you culture it first and then heat fix, stain etc. I don't think heat fixing the blood stain would damage the bacterial cells so much as make it hard to differentiate the bacterial cells from the dead, shriveled, ruined blood cells, unless maybe you have like an electron microscope or something.
Green
It usually consists of polysaccharides,[1] but can be composed of other materials (e.g., polypeptide in B. anthracis). Because most capsules are water soluble[citation needed], they are difficult to stain using standard stains because most stains do not adhere to the capsule. For examination under the microscope, the bacteria and their background are stained darker than the capsule, which doesn't stain. When viewed, bacterial cells as well as the surface they are on, are stained dark, while the capsule remains pale or colorless and appears as a ring around the cell.
Methylene blue stain is used to stain plant and animal cells.
Endospore staining is a differential stain used to detect the presence and location of spores in bacterial cells.
A basic dye used in gram staining is crystal violet.
The gram stain uses a decolorizing product so it is possible to differentiate between the gram and the gram cells. Gram positive cells stain purple in color.
A negative stain will stain the background with an acidic dye, such as Nigrosin. This procedure is used to demonstrate capsules. This technique brings the specimen off of the background for more adequate viewing purposes.
Gram staining refers to separating bacterial species into two groups, gram-positive and gram-negative, which defines the physical and chemical properties. Skipping a step in this process could result in a mixed group of the bacterial species.