9. Microscopes

A scientist is examining more than one species of bacteria under a microscope at the same time. The scientist decides to differentiate the bacterial cells based on their cell wall/cell envelope structure. Which staining technique should she use?

A scientist has a sample containing a variety of different bacteria species. She wishes to identify which bacteria in her sample are of the genus Mycobacterium. Mycobacterium have a wax-like, nearly impermeable cell wall which contains mycolic acid. Which type of staining technique should the scientist use to identify the Mycobacterium?

What is the purpose of a counterstain in the acid-fast stain?

Assume you stain Bacillus by applying malachite green with heat and then counterstain with safranin. Through the microscope, the green structures are

a. cell walls.

b. capsules.

c. endospores.

d. flagella.

e. impossible to identify.

Fill in the blanks: ___________________ are dormant structures that certain bacteria can make. These structures can be seen using the structural stain called the ___________________.

Which of the following would you expect to find in acid-fast cell walls? Select all that

apply. (NCLEX/HESI/TEAS)

a. Peptidoglycan

b. Phospholipids

c. Lipopolysaccharide

d. Lipid A

e. Mycolic acid