Why do you think the presence of grease or dirt on a glass slide will result in a poor smear preparation cite two or three reasons?

Why do you think the presence of grease or dirt on a glass slide will result in a poor smear preparation cite two or three reasons?

Why do you think the presence of grease or dirt on a glass slide will result in a poor smear preparations? Bacteria will attach to the grease or dirt and wash away when staining. 2. It can also diminish the microscopic light making it hard to see the cells.

What is the purpose of passing the slide with the bacteria specimen through the flame of a Bunsen burner?

Heat fixing is an easy and efficient method, and is accomplished by passing the slide briefly through the flame of a Bunsen burner, which causes the biological material to become more or less permanently affixed to the glass surface. Heat fixed smears are ready for staining.

How does heat fix smears to the glass slide?

Heat-fix the dry smear by running the slide quickly through the flame a few times. If your fingers get hot, you have heat-fixed TOO MUCH. The heat-fixing will coagulate some of the protein material and cause the suspension to adhere to the glass slide. A different dye will be used for each bacterium.

What is the purpose of a smear?

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 the reasons for heat fixing the smear?

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.

What is the importance of noting the presence of dirt paint grease and putty of the undisturbed glass of the window?

Whenever possible, the exterior and interior surfaces of the glass must be indicated. The presence of dirt, paint, grease or putty may indicate the exterior surface of the glass.

Why must slides used in a smear preparation be grease free?

After removing the soapy filling with a clean cloth the surface becomes clean and grease free. If the slide is perfectly clean drop can spread on its surface in a thin even film, otherwise the water collects into small drops and film cannot be made.

What causes a flame in a glass tube?

In the above activity, The vapours of wax coming out of the glass tube could be the cause of the flame produced. When the candle flame is steady, introduce a clean glass plate/slide into the luminous zone of the flame . Hold it there with a pair of tongs for about 10 seconds.

Why do you air dry a glass slide?

Air-drying adheres the bacteria to the slide. Air-drying ensures that the smear is thin enough to stain. The air-drying step coagulates the proteins in the bacteria. Drying helps remove excess water to ensure optimal heat fixation. Why does the presence of grease or dirt on a glass slide result in a poor smear preparation?

Why is it important to pass slide through Bunsen burner?

The grease and dirt can create artifacts that interfere with accurate visualization of the organisms. During heat fixation, it is important that the slide be passed only 2-3 times through the outer portion of the Bunsen burner flame to prevent overheating. Overheating can cause which of the following to occur?

What are the functions of glass slide and cover slips?

Cover slips are small squares of glass that cover the specimen placed on the microscope slide. They flatten the specimen for better viewing and also decrease the rate of evaporation from the sample, both in wet and dry mounted slides, explains the Newton website. If a stain or other liquid has been added, the cover slip keeps it on the specimen.