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 the purpose of the smear preparation?

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.

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 is the purpose of fixation in smear preparation quizlet?

Heat fixation ensures the elimination of contaminating organisms from the smear preparation. Heat fixation adheres the cells to the slide and coagulates the bacterial proteins, effectively killing the bacteria.

How is a bacterial smear prepared quizlet?

Bacterial Smear Preparation

What is smear quizlet?

Terms in this set (15)

A dried preparation of bacterial cells on a glass slide is called a. smear.

How is bacterial smear prepared?

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. A good smear preparation is the key to a good stain.

What is the purpose of heat fixation in smear preparation?

Heat fixing kills the bacteria in the smear, firmly adheres the smear to the slide, and allows the sample to more readily take up stains. Allow the smear to air dry.

Why is it important for a smear to be thin?

Why is it important to make the smear thin? thin smear, because the thickness will determine whether or not you can visualize individual cell morphology(form), their arrangements, or details regarding gram reaction or internal structure.

Why is heat fixation necessary for smear preparation?

Heat fixing kills cells, and adheres them to the slide. Cells will be rinsed off the slides if they are not heat fixed properly.

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 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.

Why is it important to examine bacteria on smears?

The smear is a means of estimating the number of acid-fast bacteria present, reported as the Bacterial Index (BI), and is important in determining the type and severity of disease as well as assessing the response to treatment.

What is blood smear preparation?

Preparation. A blood smear is made by placing a drop of blood on one end of a slide, and using a spreader slide to disperse the blood over the slide's length. The aim is to get a region, called a monolayer, where the cells are spaced far enough apart to be counted and differentiated.

What are the two reasons that you must do the smear preparation for any staining procedure?

There are two important things to consider when preparing a slide for staining: The bacteria must be evenly and lightly dispersed. If there are too many bacteria on the slide they will form a big glob and you will not be able to see the morphology of the individual cells.

What is the important use of thick blood smear preparation?

Thick smears consist of a thick layer of dehemoglobinized (lysed) red blood cells (RBCs). The blood elements (including parasites, if any) are more concentrated (app. 30×) than in an equal area of a thin smear. Thus, thick smears allow a more efficient detection of parasites (increased sensitivity).

What is smear study?

A blood smear is a sample of blood that's tested on a specially treated slide. For a blood smear test, a laboratory professional examines the slide under a microscope and looks at the size, shape, and number of different types of blood cells.

How do you prepare a smear prep?

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.

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.

How does smear preparation of cells from a liquid medium differ from preparation of cells from a solid medium mark all that apply?

How does smear preparation of cells from a liquid medium differ from preparation of cells from a solid medium? Water is applied to the slide before emulsifying cells from a solid medium. It is important that the smear is thick in order to ensure that the stain will be retained on the slide.

What is the purpose of bacterial heat fixation?

Fixation increases the adherence of bacterial cells, and the most common method employed is heat fixation (Ederer and Lund, 1981). This is completed by passing a slide of bacterial cells through a flame until the underside of the slide is warm to the touch. Chemical methods of fixation have also been described.

How does smear preparation of cells from a liquid medium?

how does smear preparation of cells from a liquid media differ from preparation of cells from a solid medium? To prepare cells from solid media, cells must be mixed in 1-2 drops of water on the slide. Two to three loopfuls if cells from liquid media can be transferred directly to the slide.

What are the two purpose of heat fixation?

What are the two purposes of heat fixation when making a smear? Heat fixation kills bacteria without destroying it causing it to stay fixed on theslide. Heat fixation kills bacteria without destroying it causing it to stay fixed on the slide .

Why would you need to add water to your slide when preparing a smear from solid media?

If you don't completely air dry your slide, you will end up boiling your microorganisms when heat-fixing. 2. When mixing bacteria with water, if you over mix it can result in inaccurate cell patterns. 3.

Why is the number of cells present in a smear preparation of such critical importance?

Why is it important to limit the quantity of the cells to prepare a smear? If too many cells are used to create a smear, it will be difficult to distinguish individual cell shapes and arrangements from the large clumps of cells.