mibo lab exam 1 Flashcards
used to carry the microscope (with base)
arm
used for carrying microscope (with arm)
base
collects and concentrates light into a tight beam on the specimen
condenser
produces light to be passed through the specimen and into the objectives
light source
adjusts amount of light being emitted from the light source
light intensity knob
controls distance between specimen and objective by raising/lowering the stage in large increments
coarse focus adjustment knob
controls distance between specimen and objectives by raising/lowering the stage in small increments
fine focus adjustment knob
magnifies the specimen image
objective lenses
platform that holds the specimen
stage
allows image to be viewed with magnification
ocular lenses
move clamped specimen across the stage
translational control knobs
how to properly clean up your bench space
- dispose of all materials contaminated with organisms properly
- return equipment to the proper storage area
- discard all old cultures and slides into the appropriate waste containers
Does talking or leaving dishes exposed to the air for prolonged times affect the amount of culturable microbes on a TSAYE medium agar plate?
yes, the longer the plate is out, the more likely culturable microbes from airborne microbes in the lab show up on the agar plates
What were the different handwashing techniques used? What do the results of this indicate about under which conditions are more or less effective at removing microbes?
rinsing under water, rubbing hands, different time intervals, water temp
longer hands are rubbed under running water, the more effective technique
What are implications for improper handwashing for both a) you leaving the lab, and b) a healthcare setting?
a) you can spread pathogenic microbes that you worked with in the lab to your surround environment
b) in healthcare you can infect yourself with microbes from your patients, or spread microbes between patients which can have detrimental effects
Describe the purpose of ‘aseptic’ technique
used to avoid contamination which cannot be visualized but can alter experimental results
reduces the risk of spreading microbes
Describe the order of steps to perform a culture transfer following aseptic technique
hold sterilized loop in dominant hand
remove cap w/ little finger
pull cap off
pick of cells with sterilized loop
place cap then put down tube
transfer cells to tube containing medium
Describe the steps we use to streak for isolation
- label plates as indicated
- use sterile loop to inoculate top of plate and spread it back/forth
- Spread modest amount of culture in small patch
- get a new stick and pass through previous patch and streak a small new area nearby
- get a new stick and pass through previous patch and streak a larger new area nearby
- get a new stick and pass through previous patch and streak a smaller/untouched area nearby
What does the antibiotic cycloheximide do?
inhibits protein synthesis in eukaryotes and therefore inhibited the growth of fungi on plates where it is present
What other additional features would you’d want to include when describing colony morphology?
color, size, texture
What is the individual dilution factor (IDF), how do you calculate it?
describe the dilutions resulting from transferring a sample to a volume of diluent solution
- volume of sample/ volume or sample + diluent
What is the total dilution factor (TDF), how do you calculate it?
how dilute a particular sample is relative to the original sample,
- product of all individual dilution factors (IDF x IDF x IDF… etc)
Do you account for the volume used for plating when calculating the CFUs /mL in your original sample?
How do you go from CFUs/mL of your original sample to total CFUs in your original sample?
CFU/mL = average colony forming units of plaque forming units on the plate/volume of the sample X TDF of the sample
