What are the two types of smear preparation?

Four different types of smear preparation methods (conventional method, blood film method, drop and rest method, and water-wash method) were carried out according to the standard reference as described below.

What is smear preparation?

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 are 2 purposes served by preparing a smear?

The purpose of making a smear is to fix the bacteria onto the slide. Fixing the bacteria will preserve the morphology of the cells long-term. Also, fixation assists the cells in adhering to the slide, so that the cells do not fall off the slide during the staining procedure.

What are the two methods of fixing a smear?

Fixation. The fixation procedure is the same regardless of smear source, plate or broth. There are two methods of adhering your bacteria to the slide, heat fixation or methanol fixation.

What are the steps in the smear technique?

Smears preparation from a Solid Medium

Using a loop, place one to two loops of water on center of slide. Heat fix the smear over flame of Bunsen burner by rapidly passing slide 3-4 times over flame. Examine each slide for the confluent, whitish film or haze and record your results in the Lab Report.

Bacterial Smear Preparation

What are the different types of staining techniques?

What are the specific aseptic techniques followed during the preparation of bacterial smears?

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 smear preparation What is the importance?

The preparation of a smear is required for many laboratory procedures, including the Gram-stain. The purpose of making a smear is to fix the bacteria onto the slide and to prevent the sample from being lost during a staining procedure. A smear can be prepared from a solid or broth medium.

What is a smear in microbiology?

A bacterial smear is a thin layer of bacteria placed on a glass blade and «fixed» by heat or other, partly to ensure that they remain attached to the glass, for coloring. It can be prepared from a solid medium or broth. Then a coloring is applied.

What are the types of blood smear technique?

The most common technique of blood smear preparation is called the “wedge or push” technique. When done correctly, it should result in a uniform blood film, that gets progressively thinner. A small drop of blood is placed on the midline at the end of a glass slide.

What is the purpose of the smear preparation quizlet?

What is the purpose of a bacterial smear? Prepare a sample of bacteria that adheres to a slide. The sample can then be stained so as to better view the bacteria.

What is a direct smear?

A direct smear is made from a clinical specimen. It can be used to: Guide the physician on initial choice of antibiotic, pending results of culture and sensitivity. Judge specimen quality. Contribute to selection of culture media, especially with mixed flora.

What is dry smear?

A new dry smear-rehydration technic is described. Slides prepared in such a manner invariably contained greater numbers of cellular elements. This method greatly reduces the large "wash-off" loss observed by us (and others) when slides are prepared by wet fixation.

What are two important qualities of a good bacterial smear?

1. Cells that adhere to the slide and does not wash off during staining and washing procedures. 2. No shrinkage of cells.

What is difference between Gram positive and Gram negative bacteria?

In 1884, a bacteriologist named Christian Gram created a test that could determine if a bacterium had a thick, mesh-like membrane called peptidoglycan. Bacteria with thick peptidoglycan are called gram positive. If the peptidoglycan layer is thin, it's classified as gram negative.

What is the difference between sterile and aseptic technique?

Although aseptic and sterile both basically mean “germ-free,” sterile is more likely to describe medical environments, products, and instruments that have been cleaned (sterilized). Aseptic is more likely to describe techniques that keep an environment in its sterile state.

What are some aseptic techniques?

Why is aseptic technique important during laboratory activities like smear preparation?

Why is aseptic technique important during laboratory activities like smear preparation? Proper aseptic technique aids in keeping microbes from spreading to other surfaces, where they might be contacted by others in the lab.

What are 2 types of stains?

The types are: 1. Simple Staining 2. Differential Staining 3. Gram Staining 4.

What is stain preparation?

In preparation for staining, a small sample of microorganisms is placed on a slide and permitted to air dry. The smear is heat fixed by quickly passing it over a flame. Heat fixing kills the organisms, makes them adhere to the slide, and permits them to accept the stain.

How direct smear is performed?

Once a sample is obtained, a direct fecal smear is made by spreading a thin film of feces on a glass slide and adding a few drops of saline. The slide is then examined under a microscope for evidence of microscopic organisms. A fecal smear can also be used to examine fecal cytology—the cells contained in the specimen.

What is the difference between direct and indirect staining?

When a staining procedure colors the cells present in a preparation, but leaves the background colorless (appearing as white), it is called a direct stain. If a procedure colors the background, leaving the cells colorless (white) it is called an indirect or negative stain.

How is a fecal direct smear prepared?

Smear a small quantity of faeces on a clean microscope slide. Mix with a few drops of water or physiological saline. Place a coverslip over the smear. The faecal material should not be left in a lump in the centre of the coverslip but evenly spread so that the microscope illumination can shine through.