Day 12 - Antibiotic Test and Hamburger Extract

Antibiotic Test

First step first, we took a plate and streaked it all over with our bacteria. We then added the antibiotic disks over the streak plate, over the numbers we had written on the underside of the plate. If the discs secret antibiotics, then bacteria around it will not grow and make a clear zone where bacterial colonies are killed; you won't see bacteria growing around disk. The larger clear zone, the better the antibiotic.
To put the disks on, you take the 70% ethanol, and dip the forceps in it. You then burn the alcohol off the forceps, take the sample antibiotic out of the package, and lay it on the dish over its corresponding number from below:

Antibiotic set up

Antibiotics:
1. Penicillin
2. Erythromycin
3. Chloramphenicol
4. Novobiocin
5. Augmentin - very old

Oils Test

To see if they have any antibiotic affect, we used the same technique as above. 5 microliters of oil were deposited onto a sterile piece of paper, after the forceps had been sterilized. Each sterile piece of paper was put over the corresponding number below:

All of the oils.

Oils:
1.Clove
2. Cinnamon
3.Thyme
4. Eucalyptis
5. Ginger

Oil and Antibiotics, ready to go into incubator.

Hamburger Extract Test

The way antibodies work is that each antibody can bind with two antigens. Antibodies bind only with specific antigens. This test determines whether the protein in the middle well is bovine (cows) albumin or if it has been contaminated with other meats. Albumin is in all blood and maintains osmotic potential. The way to make an anti-horse bovine is to add a horse albumin to a goat. The goat's system will see this as foreign and will form antibodies against this. We use this to detect the horse albumin, and therefore horse meat.

To determine if the hamburger extract has contamination with other meats, one group does template II and the other template III. We were told to do the hamburger extract test (template I), to see if the hamburger was pure. First, we had to make four holes in the agar using a dropper to suck up the agar, and pulling it out to make the wells. After the 4 holes are made in the pattern assigned, we put hamburger extract, goat anti-horse albumin, goat anti-bovine albumin, and goat anti-swine albumin, each in one of the four wells, adding one drop of each to its corresponding hole, and wait until tomorrow to see the results (this test did not have to be incubated).

Plate used for Hamburger Extract

*App of the Day - Our test was found to be pure hamburger meat. It was free from other contamination. But, that hamburger meat may be full of other things that we don't even realize. Nitrate is one of the preservatives often used in meat. It also might be interesting to test a hot dog with this method. Hmm.. maybe some things are better off not known.