BIO 304 Review for Lab Practical Spring 2006

Microscope: know all the parts of the light microscope, and its proper use and storage. You may be asked to bring a specimen to focus under oil after the instructor has “messed up” the scope. What is the function of the oil in oil immersion? What does ‘parfocal’ mean? Don’t worry about phase contrast or dark field microscopy.

Smear preparation: how do you make a smear? Why do you make a smear?

Staining: What is a chromophore, and what does its charge have to be if it is going to stick to a bacterial cell? If it will stain only the background? What are these two staining techniques called?

Differential staining:

Gram staining-know all the steps and why they work, be able to recognize a slide that has been prepared as a Gram staining.

Types of micro lab media and their proper use: plate, broth, stab/deep, slant

Aseptic technique: purpose of flaming tools? purpose of flaming the lip of the tube? of working near the flame?

Dilution techniques:

Streak plates-how is it done? What is the goal of a streak plate?

Serial dilutions-“Yes Virginia, there will be a serial dilution problem on the lab practical.”

Food microbiology: what foods have higher or lower bacterial counts and why?

Special Media: General purpose, selective, differential. What are they? (Blood agar, EMB, MSA) Why are they used and for what organisms?

Normal flora of the skin and upper respiratory tract: what are they, what special media were used to look at them. What are the hemolytic reactions on blood agar? What are the major characteristics of Staphylococci and Streptococci, how would you tell them apart?

Identification of an unknown bacterial culture: can I read a dichotomous key?

Carbohydrate metabolism: starch hydrolysis, fermentation tubes, O/F tubes, MR-VP test. What are these tests telling me? How are they read? Given data from a set of tubes, can I make a conclusion regarding the carbohydrate metabolism of the culture?

Protein metabolism: MIO tube, Phenylalanine slant, peptone iron deep, litmus milk, citrate slant, gelatin, urea slant. Do I know what all these tests look for? Can I read the tube and make a valid conclusion?

Catalase and oxidase test: What are these tests for? How are they performed? How are they read? Given data from carrying out these tests, can I make a conclusion regarding the characteristics of respiration in the culture?

Physical and chemical control of microorganisms: UV radiation. What protects a culture from UV radiation? How was the experiment done? Why did it work? How does UV kill? Can I give an example of how UV is used to control bacterial contamination in a real life situation? Hand scrubbing: What is the difference between normal flora and transient flora? Is the skin ever sterile? Antiseptics/disinfectants: what is a time course of exposure to a chemical agent? In regard to controlling microbes, how do surfactants work? How does ethanol work? How does Lysol work? Antimicrobials and the agar diffusion method: what are the limitations of the agar diffusion (Kirby-Bauer) technique? Given data from the test, can I interpret a chart and determine if a culture is sensitive or resistant to a drug?