Question

Simple Staining Data Interpretation Please type the answers to the following questions below (double spaced) and attach the data collection sheets when you hand in this lab report. 1. Define acidic and basic dyes. What is the purpose of each? 2. What is the purpose of fixing a slide that is to be stained? 3. Why are specimens to be stained suspended in sterile saline or distilled water? 4. Which of the microscope objectives is most satisfactory for studying bacteria? Why? 5. List and define the basic shapes of bacteria. What are the dimensions of an average bacillus in micrometers? In centimeters? 6. List at least three types of bacteria whose names reflect their shapes and arrangements, and state the meaning of each name. 7. For what reason do we need to stain bacteria? 8. Which stain gives the best clarity for each organism? Why? 9. Did you have trouble viewing some of the slides you made? If so which ones? State some errors you might have made in your staining technique? How would you correct these errors next time?

Answer 1

Question 1: acidic dyes are referred to as the dyes that would be having a negative charge such that these would be able to bind to the positive structures present in the cell. These re used less often intne microbiology lab. An example of an acidic stain is the capsule staining, which would be staining the background. Examples of stain are India ink, acid fuschin, picnic acid as well as nigrosine.

Basic dyes are the ones that would be having a positive charge and would be binding to molecules that are negatively charged. These molecules would be nucleus acids. These are used more commonly since, the bacterial surfaces are negatively charged, due to the presence of teichoic acid. These are used more commonly. Examples are safranin, methylene blue, crystal violet or basic fuschin.