Basic stains, such as methylene blue, Gram safranin, or Gram crystal violet are useful for staining most bacteria. These stains will readily give up a hydroxide ion or accept a hydrogen ion, which leaves the stain positively charged.
Is crystal violet a basic dye?
The gram stain utilizes crystal violet as the primary stain. This basic dye is
positively charged
and, therefore, adheres to the cell membranes of both gram negative and positive cells. After applying crystal violet and waiting 60 seconds the excess stain is rinsed off with water.
What are the examples of simple staining?
Simple staining is also called as monochrome staining or positive staining. Examples of simple stain are
Methylene blue, Safranin
What color is a simple stain?
It is a cationic dye (positive charge) which stains the cell
a blue color
.
Is crystal violet a differential stain?
One commonly recognizable use of differential staining is the
Gram stain
. Gram staining uses two dyes: Crystal violet and Fuchsin or Safranin
Is a simple stain positive or negative?
Simple staining involves directly staining the bacterial cell with a
positively charged dye
in order to see bacterial detail, in contrast to negative staining where the bacteria remain unstained against a dark background.
What three basic shapes of bacteria can be seen in a simple stain?
The three basic bacterial shapes are
coccus (spherical), bacillus (rod-shaped), and spiral (twisted)
, however pleomorphic bacteria can assume several shapes. Cocci (or coccus for a single cell) are round cells, sometimes slightly flattened when they are adjacent to one another.
What are the disadvantages of simple stain?
Disadvantages.
It does not give much information about the cell apart from the bacteria’s morphological characteristics
. Through simple staining, we cannot classify a particular type of organism.
What color will it appear when simple stained with crystal violet?
First, crystal violet, a primary stain, is applied to a heat-fixed smear, giving all of the cells a
purple color
.
How do you describe a simple stain?
Simple staining
involves directly staining the bacterial cell with a positively charged dye in order to see bacterial detail
, in contrast to negative staining where the bacteria remain unstained against a dark background.
What is crystal violet stain used for?
In the medical community, it is the active ingredient in Gram’s Stain, used
to classify bacteria
. The dye destroys cells and is used as a moderate-strength external disinfectant. It is widely used as a purple dye for textiles such as cotton and silk. It provides a various deep violet colors for paints and printing ink.
What happens if you reverse crystal violet and safranin stains?
If there is a reversal of crystal violet and safranin stains, then
the cross-link between iodine and crystal violet won’t happen
, and during decolorization, the safranin will fade away. Ans also, as crystal violet stain is used in the last, it will make all cells purple.
Why does the crystal violet stay on the Gram positive bacteria?
Gram positive bacteria stain violet
due to the presence of a thick layer of peptidoglycan in their cell walls
, which retains the crystal violet these cells are stained with.
Is an example of negative stain?
Some suitable negative stains include
ammonium molybdate, uranyl acetate, uranyl formate
, phosphotungstic acid, osmium tetroxide, osmium ferricyanide and auroglucothionate. These have been chosen because they scatter electrons strongly and also adsorb to biological matter well.
What is another name for basic and acidic stain?
Amphophilic
– It is a term used to indicate that the tissue stains with both the basic and the acidic dyes. Neutrophilic – No special affinity for either the basic or acidic components of a dye.
What can be observed using a simple stain quizlet?
Simple stains cannot determine if a cell is Gram-positive or Gram-negative, nor if endospores or other cellular features are present. A lab mate performs a simple stain with crystal violet. They observe that all the cells are
purple
and conclude that their unknown bacterium is Gram-positive.
