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Unformatted text preview: Lab Manual Create a subheading in your notebook: Discussion of Serial Dilution Method o Take notes in your science notebook o Also refer to the “Background Information”section at the end of the Lab Manual Procedure: Record any intentional or unintentional modifications to this procedure in your science notebooks 1. Record the code letter of your sample in your science notebook. This code letter represents which chicken farm your sample came from. 2. Each pair should take three kanamycin plates (labeled K) and three unlabeled plates. On the top of each lid, write your names, the date, your section number, the code letter of your sample, and label one of each 10‐2, 10‐4, and 10‐6. 3. Take 3 empty sterile microtubes and label the top with the dilutions you will make (i.e., 10‐2, 10‐4, 10‐6). Using sterile technique, add 990μl of water into each microtube. Use sterile technique so that you don’t introduce unwanted bacteria into the tubes (refer to Fig 3). 4. Each person will make their own dilutions. On each bench, there is only one microtube containing the concentrated bacterial suspension so you will need to share this tube. Take the bacterial suspension microtube and mix it using a gentle flicking motion (as demonstrated by your TA). This is a very important step – if you do not adequately mix the suspension you will not get a representative sample of bacteria. Each person will remove 10μl from the microtube and use this as the starting sample to make their three, 100‐fold serial dilutions. a. At each step, keep the bacteria well suspended by flicking the tube before you remove your sample. 5 5. Line up all of your petri dishes in order of dilution (i.e., 10‐2 to 10‐6). Using a pipettor, inoculate each Petri dish with a 100μl sample of bacteria from the appropriate microtube (i.e., 10‐2 to 10‐6). You must use a fresh pipette tip for each dilution. ‐6
6. Distribute the bacteria evenly on the agar surface of your 10 plate using sterile glass beads. Take a capped test tube containing sterile beads from the test tube rack and carefully pour all of the sterile beads onto th...
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This note was uploaded on 02/06/2014 for the course BIO 110 taught by Professor Hass during the Fall '11 term at Penn State.
- Fall '11