Question

-Fohandl NO Cont. Lat Exercise 5-Smear Preparation Procedure to prepare a smear(from liquid and solid media) - be able to correctly order all steps. Know which tools to use for making the smear. What is a target circle? Why is important to draw it? Why is it important to completely air dry the smear before heat fixing? What are two most important things that occur in heat fixing? Advantage/disadvantage of heat fixing Exercise 6-Simple Staining Basic -Cationic(+) vs. Acidic Dyes -Anionic(-) chromophores What is stained with a simple stain? Cell? The background? What three pieces of information can be gained? Sze-shape- AYansemenT Differences between simple and differential staining. Procedure (name of dye/stain used and sequence of steps) Know the names and appearances of the bacteria, Genus and species that we stained in this lab. Be able to recognize a simple stain prepped slide and identification of bacteria on it. Be able to describe the size, shape and arrangement of a bacteria on any stained slide. Exercise 7-Negative Staining Procedure for preparing negative stain slides (name of the stain and technique used for introducing and spreading organisms) What is stained in negative staining? Cell? The background? What is the name of the stain used in Negative Staining? Is the stain Basic - Cationic or Acidic -Anionic? Which bacteria Genus and species did we stain in this experiment? Appearance of organism and background. Do you heat fix these slides? What advantage does this method offer over simple stain smears that have been heat fixed? Disadvantages? Be able to recognize a negative stain prepped slide and identification of bacteria on it.

Answer 1

5)1. Smear preparation :-

Slide Preparation: Step 1

A sample of a bacterial colony must be mixed into water or saline.

SP: Step 2

Using a pipette, apply a small drop of the bacterial fluid to a clean glass slide.

SP: Step 3

Smear the fluid evenly across the surface of the slide with the edge of a cover slip. Allow slide to air dry.

SP: Step 4

Turn on Bunsen burner. Holding the slide with forceps, pass it through the open flame 2 or 3 times (this fixes the cells to the slide).

SP: Step 5

The slide is now ready for a staining process.

5)2. Tools required to make a smear :-

Inoculating loop, Bunsen Burner, Glass Slide, and Clothespin

5) 3. Target circle - Area of where the sample will be located. It is important too draw the target circle on a slide as it help designate the area in which you will prepare the smear

5)4. it important to completely air dry the smear before heat fixing because Attempting to heat fix the slide while wet will cause the cells to lysis.

5) 5 . The two most important things that occur in heat fixing is kills bacteria and adheres bacteria on slide .