Reference no: EM131655447

Bacterial Morphology and Staining Techniques

Exercise 1: Direct and Negative Stains

Questions

A. What is the purpose of heat fixing? Why did the slides need to be heat fixed during the direct stain but not during the negative stain?

B. Define the three major types of bacterial shapes. Which of these did you observe in the exercise?

C. Is Crystal Violet a basic substance or an acidic substance? Is Congo red a basic or an acidic substance? Describe how you were able to arrive at this conclusion and relate your findings to your experimental observations.

Exercise 2: Differential Stains

Questions

A. Describe the difference between Gram-negative and Gram-positive bacteria. Which type of bacteria are most often treatable with antibiotics and why?

B. List the steps of the Gram stain technique and describe the purpose of each. Be sure to include a description of what color the bacteria appear during each step.

C. What is the major advantage of a differential stain, such as the Gram stain, over a simple stain? Was this observed in your experiment?

Attachment:- Assignment.rar