Pour the contents of one of the test tubes into the other and a reaction should occur and you should see a white precipitate of barium sulfate form. Then, centrifuge it for 1 minute. On the side, weight a boiling test tube containing 2 boiling chips. When the separation is complete, remove the small test tubes from the centrifuge and decant the supernatant into the boiling test tube. Add 1 mL of deionized water to the small test tube containing the precipitate and mix it and centrifuge it for 60 seconds.
Biology lab: Methods and Results February 14, 2012 Genus species Methods: In order to conduct our experiment we started off with two petri dishes, six antibiotics and two types of bacteria to run our experiment. The bacteria that were being used in this experiment were E. coli and S. Marscescens. The antibiotics that are being used to combat the bacteria are called Penicillin (1929), Streptomycin (1947), Erythromycin (1952), Ampicillin (1961), Gentamicin (1971), and Ciprofloxin (1987). In the two petrib dish, each is individually chosen to be for E. coli and for S. Marscensen. At the bottom of the petri dishes we level it with four quadrants to make sure that each of the antibiotics were placed in the right quadrant and be able to see how the bacteria acted in respect to the placement of the antibiotic.
Why is this necessary? Obtain an appropriate amount of 5.00 M NaCl and fill your 25 mL buret. Pipet a 20.00 mL aliquot of 0.100 M acetic acid solution into a 100 mL beaker, add a magnetic stirring bar, and then set up the titration apparatus as indicated in Figure 1. Record the initial pH and then begin titrating. You will titrate in 0.25 mL intervals for the first 2 ml and then in 1 mL intervals until a total of 6 mL of 5.00 M NaCl has been delivered.
The seaweed will be cut and weighed (6 grams) and transferred into 150 mL solution. Using 40 mL of distilled water the seaweed is heated just under boiling for five minutes. After cooling, a filter will be used to remove the seaweed from the extract. The goal is to transfer 2-3 mL of filtrate into the evaporating dish. We now slowly pour the solution into a funnel with filter paper.
The total sample volume was made up to 13 μL by adding water. The reaction vial was placed on ice, and was added 2 μL each of 10x NTP labeling mixture, 10x transcription buffer, and T7 RNA polymerase. 1μL of protector RNase inhibitor was also added, and the contents in the vial were mixed gently and incubated for 2 hours at 37 degree Celsius. To remove the template DNA after transcription, 2 μL of DNase I was added and incubated for about 15 minutes at 37 degree Celsius. The reaction was stopped by adding 2 μL of 0.2 M EDTA at pH 8.
Then both test tubes were placed in a room temperature bath. Then 3-4 drops of iodine were added and adjusted. After 5 minutes, the position of the dye was recorded and then after every 2 minutes for 20 minutes the dye position was recorded. Time (minutes) Dye Position Test Tube #1 pt 30OC Test Tube #2 pt 100OC 0 0.1 0.1 2 0.1 0.1 4 0.1 0.1 6 0.11 0.1 8 0.11 0.1 10 0.12 0.1 12 0.12 0.1 14 0.13 0.1 16 0.14 0.1 18 0.14 0.1 20 0.15 0.11 Figure 1: Each test tube contained 20 pea seeds which were pretreated for 15 minutes in 0.2M sucrose solution at 30OC and 100OC. Each test tube contained a cotton ball dampened with 15% KOH, then a ball of glass wool, then 20 pea seeds soaked at the certain temperature, then another ball of glass wool, and then another cotton ball dampened with 15% KOH.
2. Add 0.6g of zinc into the beaker. Mix the zinc with a stir rod. 3. Then, wait at least ten minutes for the zinc to settle.
4. Next, the biochemical reactions tests are performed. Inoculated three Durham tubes of phenol red broth with unknown bacteria, each containing a carbohydrate- sucrose, glucose, and lactose as a substrate. Incubated at 37 degrees for 24 hrs. Colorimetric changes are used to observe fermentation and bubbles tube to check for gas.
Cylinder was rinsed with distilled water. * * 2. 2.0 ppm standard: 2.00 mL of 10.0 ppm phosphate solution was placed in a 25 mL graduated cylinder and diluted to exactly the 10 mL mark with distilled water then poured into a plastic cup labeled 2. Cylinder was rinsed with distilled water. * 3.
Compare the MPs of the once recrystallized and the twice recrystallized trimyristin. After the hydrolysis has proceeded for 45 minutes, allow the flask to cool to RT and pour the contents into a 50 mL beaker containing 8 mL of water. Carefully, in the hood, add dropwise with stirring, 2 mL of concentrated HCl (caution: corrosive liquid/noxious vapors). Myristic acid should precipitate. Cool the beaker in ice water for 10 min, with stirring, and collect the solid by vacuum filtration on a small Hirsch funnel.