0
Contamination
What else can I help you with?
Which step in the gram stain is the critical step in differentiating gram positive cells from gram negative cells?
Alcohol-acetone
Is shigella flexneri gram positive or negative?
When a gram stain is done on Shigella flexneri, the cells are light pink. This means that they are gram negative.
Why is decolorization necessary when performing a gram stain?
During the procedures of a gram stain, decolorization is necessary to remove any stain or color from the gram negative cells. When a dye is used to stain gram positive cells, both gram positive and gram negative cells retain color. Mordant is used to bind the original stain to gram positive cells so when decolorizer is used they retain color. After the mordant has been used a decolorizer is used to wash away colo in gram negative cells. Counterstains are used to stain gram negative cells to better visualize contrasting cells. An example of a decolorizer that works well is ethanol.
Does candida have a positive or negative gram stain?
Gram positive
Is HIV gram stain positive or negative?
The answer to whether HIV gram-stain positive or negative is that HIV gram-stain is negative. They retain the light red or pink color after the stain.
Are human cells gram positive?
Human cells are Gram-negative because they do not contain certain structures. More simply, if they don't have a cell wall they cannot be Gram-positive.
Why do all cells stain purple in the flagella stain but not in the gram stain?
In the flagella stain, all cells appear purple due to the basic dyes used to stain the flagella. This uniform coloration helps visualize the flagella structure under the microscope. In contrast, the Gram stain uses a series of dyes to differentiate between Gram-positive (purple) and Gram-negative (pink) cells based on their cell wall composition.
Does yogurt stain gram positive or gram negative?
Yogurt contains mostly lactic acid bacteria, which are Gram-positive bacteria. This means they will stain purple under a Gram stain.
List the steps of the gram-staining procedure in order and fill in the color of gram-positive cells and gram-negtive cells after each step?
____________Color of Gram-positive_______Color of Gram-negativePrimary stainCrystal violet_____Purple____________________ PurpleMordant:Iodine____________Purple________________________PurpleDecolorizing agent:Alcohol-acetone__ Purple____________________ ColorlessCounterstain:Safranin___________Purple_________________________Red
What colors gram positive and gram negative bacteria?
Gram-positive cells are purple and the Gram-negative cells are red.
What is the current theory about the mechanism of the gram stain?
The gram stain is a basic differential stain used to determine if a bacterial cell is gram positive or negative. Gram positive cells have a thick peptidoglycan layer that will trap the crystal violet iodine crystalls and apear purple. Gram negative cells only have a thin peptidoglycan layer that allows the crystals to diffuse out of the cell and will only be seen with the application of a counterstain, such as safranin which turns the cells pink.
Do gram-positive cells carry a net positive charge?
Gram-positive does not refer to a positive charge, but to the purple color of the stain. Gram-negative bacteria do not retain the purple dye and are instead red in color.
