First, 0.4040 grams of NaH2PO4 and 0.3989 grams of Na2HPO4 were added to a 150 mL beaker, along with 50 mL of distilled water. Next, 20 drops of bromothymol blue were inserted into the solution. The program LoggerPro and a Vernier pH probe were used to calculate the pH. Then, a volumetric flask was used to measure 5 mL of the buffer solution into each of three, separate 50 mL beakers. After rinsing a volumetric pipet with 1.0 M HCl, 1.00 mL of 1.0 M HCl was transferred to one of the three beakers.
The water then became saturated. 4. The cold beaker was Beaker A. After Beaker A was tested, Beaker B was tested, which had been sitting on a heater keeping the water inside warm at 30 degrees Celsius. It was filled with KCI five times by the 5g spoon, and then five times again by the 1g spoon.
I added a few drops of 3% Hydrogen Peroxide and it resulted in bubble formation. The positive gram stain and positive catalase test indicated that the organism belonged to the Staphylococcus Genus, which meant it was now time to pinpoint the species based on differential and selective biochemical tests. To ensure that my genus identification was correct I performed a Bile Esculin Slant with a fish tail streak on my unknown bacteria. This test resulted in neither growth nor a black precipitate; therefore I could conclude that my unknown was not Streptococci or Enterococci but indeed Staphylococcus. Next I observed the isolation streak on my Blood Agar Plate and found pinpoint, round, entire and flat colony morphology as well as an alpha hemolytic reaction pattern, indicating red blood cell ion leakage which is characteristic of S. epidermidis.
What should this contain? j Count up how many iodine drops you have used, each one equals 10 seconds of reaction time. k Repeat the whole procedure with another of the pH buffers or pool your results with others in your class. l Collect repeat data if there is time. m Plot a graph of time taken for starch to break down against pH.
Place micropipette #1 on the laboratory balance. Measure its mass to the nearest 0.01 g and record this value in Data Table 1. 3. Fill the micropipette with tap water as completely as possible. Place it on the balance and measure its mass to the nearest 0.01 g. record the mass in Data Table 1.
• Fourth, clamp the other end of tubing, leaving about a 2 cm. pocket of air. • Fifth, label the tubing with a letter of solution in bag. • Sixth, rinse each bag with water then blot dry with a paper towel. • Seventh, measure the mass of each bag and record data.