Microscope Lab Essay

Please answer these questions then place them in the drop box for this lab. Use Microsoft word if possible.

The Methyl Red test is a differential test for bacterial respiration used to differentiate strains of coliform bacteria capable of performing mixed acid fermentation that will lower the pH despite the phosphate buffer (http://faculty.deanza.fhda.edu). Mixed acid fermentation is confirmed by using methyl red as an indicator. It is red ant pH 4.4 and below, yellow at pH 6.2 and above, and orange in between. Red is a positive result reported as (+), yellow is a negative result reported as (-), and orange is negative or inconclusive.

7. How do you know that no contamination occurred when you inoculated your culture? (1 pt)

This test is used to detect if the bacteria contains any deoxyribonuclease activity. Because no color change was observed from blue to clear my unknown bacteria displayed a negative result.

6. Your lab partner hands you a slide with a new sample of a bacterium called Staphylococcus mutans. What can you deduce about this bacterium? B

1. View the three scenarios listed below. You must observe and analyze these as part of the lab.

Purpose: The purpose of this lab is to help you become a little familiar with some of the tests that can be typically performed in a clinical or research lab facility. These tests may help in determining a particular pathogen’s growth needs.

On your own and without assistance, complete this Lab 1 Answer Form and submit it via the Assignments Folder by the date listed on your Course Schedule (under Syllabus).

For the Urease test, I incoluated my Urea test tube with my unkown bacteria from a TSA plate using and inoculating loop. The Urea tube was then incubated at 37 degrees Celsius for 8 days to observe for a color change. The Urea tests for the ability of a bacteria grown in urea broth produces urease. This medium contains the pH indicator phenol red. If urease is produced the pH of the media will raise thus causing the phenol red to change from yellow to a pink color.

The petri dish was sanitized and covered in the agar. The cotton swabs used to swab bacterial samples were dampened using water. The spots around the school were swabbed and brought back to the petri dish to prepare to grow the bacteria. To get the bacteria to transfer off the cotton swab and onto the agar, the cotton swab must be rolled around the entire surface

Next heat shocks the tubes for 50 seconds, followed by icing for 10 more minutes. The heat shock increases the permeability of the cell membrane to DNA. Then add 250 milliliters of LB and incubate for 20 minutes. The 20 minute incubation following the addition of LB broth allows the cells to grow and express the ampicillin resistance protein, beta-lactamase, so that the transformed cells survive the subsequent ampicillin selection plates. Plate 100 microliters the + tubes evenly on two plates; 1 of LB and Amp, and one of LB, AMP, and ARA. Plate 100 microliters of the – tubes evenly on two plates; 1 of LB and AMP, and one on LB only.

The first task we had to perform in this lab was diluting an Escherichia coli culture and compare it to the

The number of specimen that fit in the FOV is 7 and the dimension I’m using is

For this particular assignment, I was given an unknown bacteria from my lab instructor and several procedures were performed to identify the unknown bacteria. The first procedure was completing a quadrant streak on a tryptic soy agar (TSA) plate. The purpose of streaking is to isolate single colonies or colony forming units (CFU). My inoculating loop was placed into the fire of a Bunsen burner to ensure that no other bacteria were present and allowed to cool. Next the inoculating loop was placed into the TSB of the unknown bacteria and in Quadrant I I swiped from left to right from top to bottom. After flaming my inoculating loop once again, I took my loop and from the bottom of Quadrant I, and I took the bottom part of the streak and swiped

1. Make a wet mount (Ex 12) of a small sample of the alfalfa water. Examine at 1000X total magnification using high contrast. This will illustrate how many organisms, both motile and non-motile, are present in the sample.