MMBB 255 General Microbiology
Lab Practical 1 Study Guide
Approximately 25 stations, around 4 min. at each, and no going back. 100 pts.
Questions at the back of each experiment are fair game (except for those that need a text book in order to answer)
Can you:
Use a microscope
Describe Cellular and Colony Morphologies
Do a Wet Mount, Hanging Drop, or smear
Do a Gram stain from memory (the others you can look up)
Interpret all the staining results encountered
Design an enrichment scheme for an organism if given some background info.
Streak for Isolation
Use a balance, pH Meter, and Hydrometer
Understand how fermented juices and solid foods are made
Do aseptic technique and use the correct sterilization method for various samples
Tell when there is growth in/on broth or plates
Use controls correctly
Do a serial Dilution
Do a spread plate or pour plate
Count colonies of statistical validity and calculate the starting concentration
Use a Spectrophotometer (both analog and digital)
Graph using Semi-log paper a growth curve and calculate doubling time
Interpret carbohydrate ferm., enzyme production, O2 growth requirements, + motility tests
Further Hints:
Safety. Microscope parts/operation. Be able to describe Cellular and Colony Morphologies
Know when, how, and why to use hanging drop, wet mount, and smears for samples (either from liquids or from plates or
solids).
Staining:. Types of dyes and terminology; types of techniques; how, why, and the interpretation of the Simple, Gram,
Negative, Acid-Fast, and Spore staining methods. Know the Gram stain steps, reagents, theory and a bacterial species for
the negative and positive results.
Enrichments. Define. Be able to interpret the results of the various types of enrichments we did and understand how they
enriched for whatever organisms (i.e. the key ingredients, environmental factors, etc.). Know the names of the organisms.
Food Fermentations. Know how each process works. Know the key organisms involved. Be able to analyze (i.e. titration,
pH, hydrometer, etc.)/recognize each process done in lab.
Know sterilization techniques, aseptic techniques, serial dilutions, and how to interpret a series of tubes for growth (taking
into account controls–what are they used for– and the environmental factors). What is agar and why temper it before use?
Be able to generate (graph), and label a growth curve. How to calculate doubling time. How to measure cell numbers (all
techniques mentioned).
Understand how each biochemical test works. Be able to interpret the results for negative or positive. Know also how to
determine/interpretation of motility and oxygen requirements.