In addition to the concepts listed below, please remember that the review questions at the end of each exercise are an excellent review of the major concepts you should have grasped from the exercise.

Because of the nature of the living organisms used in microbiology, there will be no open labs prior to the practical.  There MAY be some time the day before to see some of the samples, but it is recommended that you begin reviewing using the excellent photos in your lab manual.

1. Exercise 44: Handwashing
    1. What is the purpose of handwashing?
    2. Describe the correct technique for washing hands
    3. Identify potential sources of contamination when using a bar soap, a pump soap or a flip top soap.
    4. Discuss the benefits and problems in using a scrub brush.
    5. Interpret the results of a handwashing experiment
2. Exercise 1: Microscope (split into 2 stations - one on lab safety)
    1. Lab safety rules
    2. parts of microscope and function
    3. resolution
    4. parfocal
    5. purpose of immersion oil
    6. proper storage of microscope
    7. shapes and groupings (eg. staphylo?, strepto?, diplo?) of bacteria
3. Exercise 7: Simple Staining
    1. how to prepare a smear
    2. how to heat fix
    3. purpose of heat fixing
    4. appearance of cells if over-heat fix
    5. purpose of each step in the staining process
4. Exercise 8: Gram Stain
    1. steps and names of reagents in Gram stain
    2. what Gram stain differentiates between
    3. colors of Gram positive and Gram negative bacteria
    4. what kind of Gram reaction human cells would give
    5. purpose of each step in the staining process
5. Exercise 9: Acid-Fast Stain
    1. steps and names of reagents in acid fast stain
    2. what acid fast stain differentiates between
    3. colors of acid fast and non?acid fast bacteria
    4. what type of Gram reaction an acid fast positive cell would give
    5. purpose of each step in the staining process
6. Exercise 10: Endospore stain
    1. steps and names of reagents in endospore stain
    2. function of endospores
    3. two genera of bacteria capable of producing endospores
    4. colors of endospores and vegetative cells
    5. identify position of endospore in vegetative cell
    6. purpose of each step in the staining process
7. Exercise 39: Temperature
    1. Distinguish between tolerance of a particular temperature and growth in that temperature.  Which is used in classifying organisms (psychro-, meso- and thermophile)?
    2. Identify features that would make a microbe thermoduric
    3. Discuss WHY an organism, known to be a mesophile, might not grow at ANY temperature within the range of 0-100EC in this experiment (at least two reasons!)
    4. Interpret data from an experiment studying the effect of temperature on microbes
8. Exercise 14: Aseptic Technique (split into 2 stations: media and technique)
    1. determine the best type of growth media (plate, slant, deep, or broth) for a given purpose (single colonies, motility, anaerobic organisms, high concentrations of pure cultures)
    2. distinguish between selective and differential media
    3. give an example of differential and of selective medium
    4. define aseptic technique and state why it is important
    5. list steps in inoculating from a broth tube, slant, or plate to a tube, slant, deep or plate, including tools used and steps to maintain sterility
9. Exercise 15: Spread Plate
    1. explain how to do a spread plate
    2. explain the purpose of doing a spread plate
10. Exercise 16: Streak Plate
    1. determine the minimal number of different types of colonies on a plate based on colony morphology
    2. explain the purpose of a streak plate
    3. describe the procedure for doing a streak plate
11. Exercise 18: Oxygen requirements
    1. interpret the results of thioglycollate tubes and state the oxygen requirements of the organism
    2. interpret results of plates grown in aerobic and anaerobic conditions
    3. explain the operation and function of a Brewer=s jar
    4. explain how the thioglycollate tube produces anaerobic conditions
12. Exercise 19: Dilutions
    1. determine number of bacteria per ml of broth when given dilutions and plate counts
    2. know the lower and upper limits of bacterial colonies to count on a plate
    3. make dilution calculations
13. Exercise 20: Carbohydrate Fermentation
    1. pH indicator in carbohydrate fermentation tubes and color when acid is present or absent
    2. purpose of Durham tube
    3. enzymes necessary for fermentation of sucrose and lactose
14. Exercise 21: TSI
    1. advantage of TSI over carbohydrate fermentation tubes
    2. disadvantage of TSI over carbohydrate fermentation tubes
    3. what black color indicates - at top of tube; in butt of tube
    4. how to interpret results
    5. where the sulfur comes from in the reaction
15. Exercise 22: Starch Hydrolysis
    1. state the purpose of an exoenzyme
    2. interpret the results of a starch agar plate inoculated and flooded with iodine
    3. explain what the iodine shows
    4. identify a starch plate that is flooded with iodine
16. Exercise 25:ImVic
    1. SIM
        1. identify what was broken down to produce indole
        2. interpret positive and negative results
        3.  identify the reagent used in the test
        4. identify whether an organism is motile
        5. identify the structure involved in bacterial motility
        6. state the enzyme involved in the reaction that produced indole
    2. MR-VP
        1. color of methyl red indicator in presence and absence of acid
        2. importance of reading test in 48 hr
        3. purpose of Voges?Proskauer
        4. determine if MRVP tests are positive or negative
        5. state the by product that causes a VP test to be positive
        6. identify positive and negative test results
        7. identify the pH range based on the color of the medium
    4. Citrate
        1. explain why citrate utilization results in a change in pH
    5.  explain what citrate utilization tells us about the organism
17. Exercise 26: Casein Hydrolysis
    1. state what is left after proteins are hydrolyzed
    2. indicate whether an organism can hydrolyze casein
    3. state what the enzyme is that is involved in the hydrolysis of casein
18. Exercise 27: Gelatin Hydrolysis
    1. determine if gelatin hydrolysis has occurred or not
    2. importance of temperature of incubation in gelatin hydrolysis
    3. reason for placing tubes on ice after incubation
    4. reasons gelatin is not typically used in growing bacteria on solid media
19. Exercise 28: Catalase Activity
    1. interpret results of catalase test
    2. reason cells would be at an advantage if they have catalase
    3. state the by-products of the reaction in which catalase is the enzyme
20. Exercise 29: Coagulase
    1. indicate which Gram positive, catalase positive organism is also coagulase positive
    2. identify coagulase test result
    3. describe what coagulase acts on
    4. explain an advantage for a bacterium to have the enzyme coagulase
21. Exercise 30: Oxidase
    1. interpret results of oxidase test
    2. indicate what pathway cytochrome oxidase is found in
22. Exercise 31: Urease
    1. interpret the results of urea agar test
    2. identify urease medium when shown positive and negative results
    3. identify the product of the reaction that causes the color change in the medium
23. Exercise 33: Phenylalanine Deamination
    1. state the function of a deaminase and a decarboxylase
    2. interpret the results of phenylalanine agar with ferric chloride added
24. Exercise 34: Nitrate Reduction
    1. interpret results of nitrate broth tubes
    2. identify the pathway bacteria utilize to reduce nitrogen
    3. explain why you have to do a second test if the first one is negative
 
 

For questions, comments and additional information, contact mfhicks@pstcc.edu
Last Updated: June 2, 2003
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