What is smear preparation and simple staining?

What is smear preparation and simple staining?

The preparation of a stained bacterial smear involves several steps. First, bacteria are placed on a glass slide and “fixed” with heat, partly to ensure that they remain attached to the glass. Then, for simple staining, a basic stain is applied. Such a stain carries a positive electrical charge.

How do you prepare a bacterial smear for staining?

In order to heat fix a bacterial smear, it is necessary to first let the bacterial sample air dry. Then either place the slide in the slide holder of a microincinerator, or pass the dried slide through the flame of a Bunsen burner 3 or 4 times, smear side facing up. Once the slide is heat fixed, it can then be stained.

What is simple staining?

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.

Where is smear preparation used?

Smear preparation is done to prepare the organism for staining. Smear preparations are used to determine cell shape, arrangement of the cells, and internal structures. Most of the stains we will be doing utilize a smear preparation to place organisms on the slide.

What is the importance of simple staining?

Simple staining allows one to observe the morphology and arrangement of the bacterial cells. Morphology refers to “form” or shape. We can use terms like spiral, bacilli (rod shaped), and cocci (spherical) to describe cell shapes.

What are the three types of stained smear preparation?


  • Smear Preparation.
  • Simple Stain.
  • Negative Stain.
  • Gram Stain.
  • Congo Red Capsule Stain.
  • Wirtz’s Endospore Stain.

Why do we stain a smear?

The main reason you stain a specimen before putting it under the microscope is to get a better look at it, but staining does much more than simply highlight the outlines of cells. Some stains can penetrate cell walls and highlight cell components, and this can help scientists visualize metabolic processes.

What is a simple stain example?

Methylene blue is a classic example of a simple stain. This blue stain will color all cells blue, making them stand out against the bright background of the light microscope.

How many steps is simple staining?

It involves the following three steps: Smear preparation. Heat fixing. Staining.

Why is it called simple staining?

Simple staining is one of the conventional staining techniques. From the name, it is quite clear that it is a very simple or direct staining method that uses a single stain only.

What is an example of a simple stain?

What are the steps in simple staining?


  1. Clean and dry microscope slides thoroughly.
  2. Flame the surface in which the smear is to be spread.
  3. Flame the inoculating loop.
  4. Transfer a loop full of tap water to the flamed slide surface.
  5. Reflame the loop making sure the entire length of the wire that will enter the tube has been heated to redness.

What is the purpose of simple stain?