Studydroid is shutting down on January 1st, 2019

by 150306


keywords:
Bookmark and Share



Front Back
pure culture
a culture containing a single unadulterated species of cells
culture medium
broth medium
liquid medium that lacks a solidifying agent
semisolid medium
a concentration of less than 1% agar
agar slants
agar deep
agar plate
agar plate
sterilization
subculturing
wire loop
needle
cultural characteristics
heat fixation
stain
acidic stain
basic stain
simple stain
differential staining
Procedure for subculturing
1. label the tube to be inoculated with the name of the organism and your initials 2. place the tubes in the palm of your hand, secure with your thumb, and separate to form a V 3. Flame the needle or loop until the wire is red.  4. With the sterile loop or needle in hand, uncap the tubes 5. flame the necks of the tubes by rapidly passing them through the flame once 6. Slant-to-broth Transfer: obtain inoculum from slant and dislodge inoculum in the broth with a slight agitation. Broth-to-slant transfer: obtain a loopful of broth and place at base of slant. Withdraw the loop in a zigzag motion. Slant-to-agar deep transfer: obtain inoculum from slant. Insert the needle to the bottom of the tube and withdraw along the line of insertion. 7. flame the necks of the tubes by rapidly passing them through the flame once.  8. recap the tubes 9. reflame the loop or needle  
Streak Plate Method
1. place a loopful of culture on the agar surface in area 1. flame the loop, and cool it by touching an unused part of the agar surface close to the periphery of the plate, and then drag it rapidly several times across the surface of area 1. 2. Reflame and cool the loop, and turn the petri dish 90 degrees. Then touch the loop to a corner of the culture in area 1 and drag it several times across the agar in area 2. The loop should never enter area 1 again.  3. Reflame and cool the loop and again turn the dish 90 degrees. Streak Area 3 in the same manner as area 2. 4. Without reflaming the loop, again turn the dish 90 degrees and then drag the culture from a corner of area 3 across to area 4, using a wider streak. Don't let the loop touch any of the previously streaked areas. 
Spread plate method
1. place the bent glass rod into a beaker and add a sufficient amount of 95% ethyl alcohol to cover the lower, bent portion. 2. place an appropriately labeled nutrient agar plate on the turntable. With a sterile pipette, place one drop of sterile water on the center of the plate, followed by a sterile loopful of bacterium. Mix gently with the loop and replace the cover.  3. Remove the glass rod from the beaker, and pass it rhough the Bunsen burner flame with the bent portion of the rod pointing downward to prevent the burning alcohol from running down your arm. Allow the alcohol to burn off the rod completely. Cool the rod for 10 to 15 seconds.  4. Remove the petri dish cover and spin the turntable. 5. while the turntable is spinning, lightly touch the sterile bent rod to the surface of the agar and move it back and forth. This will spread the culture over the agar surface. 6. When the turntable comes to a stop, replace the cover. Immerse the rod in alcohol and reflame. 
Pour-plate technique
Moleten agar, cooled to 45 degrees C, is poured into a petri dish containing a specified amount of diluted sample. Following addition of the molten-then-cooled agar, the cover is replaced, and the plate is gently rotated in a circular motion to achieve uniform distribution of microorganisms.
How to produce a pure colony from a mixed colony
Prepare a stock (pure) culture from spread or streak plate
1. flame the straight needle until the entire wire is red. 2. after isolating a discrete colony on the agar streak plate, touch the straight needle to the surface of the selected colony 3. uncap the agar slant and pass the neck of the tube rapidly over the Bunsen burner flame 4. Inoculate the slant by draawing the needle upward in a zigzag motion along the surface of the agar. Do not dig into the agar.  5. Flame the neck of the tube and recap. 6. Flame the inoculating needle.
Label the parts of the Microscope
page 32
Magnification for oil immersion lens.
100x times 10x= 1000x Objective lense times ocular lens= total magnification
x of y cards