What is the function of crystal violet in a simple stain?

Simple Stain 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.

Does simple staining require smear preparation?

This semester you will be performing two staining procedures: A Simple Stain and a Gram stain. Both of these staining procedures begin with the preparation of a bacterial smear.

How is a smear prepared for staining?

The first step in most bacterial staining procedures is the preparation of a smear. In a smear preparation, cells from a culture are spread in a thin film over a small area of a microscope slide, dried, and then fixed to the slide by heating or other chemical fixatives.

What type of stain is crystal violet?

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.

What is a smear in microbiology?

A bacterial smear is a thin layer of bacteria placed on a slide for staining. Preparing the smear requires attention to a number of details that help prevent contamination of the culture and ensure safety to the preparer.

How do you make a smear preparation?

Culture from solid media: Using a sterile pipette, add one drop of sterile saline or sterile water to the center of the microscope slide. Aseptically pick a small amount of an isolated colony with a loop and gently mix into the drop of sterile saline or water using circular motions. Mix evenly to make a thin smear.

What is simple smear?

The simple stain technique is a rapid and effective way of preparing a bacterial smear for viewing. It is a one-step procedure in which the smear is covered with stain and allowed to sit undisturbed for a minute or so, during which the bacterial cytoplasm chemically unites with the basic stain.

How do you make crystal violet stain?

Prepare Crystal Violet Stain

1. Dissolve 2 g crystal violet in 20 ml of 95% ethyl alcohol.
2. Dissolve 0.8 g ammonium oxalate monohydrate in 80 ml deionized water.
3. Mix the crystal violet and ammonium oxalate monohydrate solutions to make the crystal violet stain. Filter the stain if necessary.