Gram Staining Lab Report

In the test for a reducing sugar, if it changes to a red orange color is it known as a precipitate as it comes out of the solution and forms solid particles dispersed around the water. The test of non-reducing sugar is striving as a result of if there is any sucrose presents it is broken down into those monosaccharides, which can be proved for using the common reducing sugar test. A positive result indicates that non-reducing sugars are present on the original sample. Sucrose fermentation it involves inoculating of sucrose broth with inoculating loop. Usually done for the differentiation of Enterobacteriaceae species.

Bacteria can be classified as gram positive or negative (difference in call wall). Gram positive bacteria have a thick cell wall of peptidoglycan (“polymer of disaccharides cross-linked by shorts chains of amino acids”), and stains purple after the staining procedure under a microscope (Todar, Kenneth,

What information does this tell you about the bacteria in the sample, and why did the colony change colour? [2 marks] This tells me that the bacteria in the sample contains coliforms such as Escherichia coli (E.coli). The colonies changed colour as the enzymes produced by the bacterial cells reacted with the red galactosidase in the agar medium, this reaction causes the colonies to turn pink making them easily

1 “substrate” and another “ enzyme.” Instead of using the distilled water, this time you are going to use different pH buffer in the enzyme test tube. In the substrate tube, add 7 mL of distilled water, 0.3 mL of hydrogen peroxide, and 0.2 mL of guaiacol for a total volume of 7.5 mL. For the enzyme tube, instead of distilled water add the pH solution (3) and 1.5 mL of peroxidase which equals a total volume of 7.5 mL. Use the dH2O syringe for our pH solution. To clean the syringe, flush it by drawing 6 mL of distilled water.

Tests include culture and non-culture diagnostics. Newer non-culture tests are nucleic acid detection tests, which include amplified and non-amplified tests. 0. Culture tests ) Thayer-Martin medium is one example of medium used for culture.

Obtain a small sample of the red epidermal cells from the stalk of the rhubarb by carefully peeling away the layer with forceps. Prepare a wet mount slide of the rhubarb tissue in distilled water only. View your slide under low power on your microscope, and then switch to high power. Draw a diagram of the field of view, and label.

Alyah al Mutairi Mr. Washington Biology class H 14.12.15 Deciding the behavior of amylase under the implement of excess pH levels Problem: To verify if amylase maintains to operate with the influence of hydrochloric acid Prelab: Independent variable: pH levels Dependent variable: The effect of pH enzyme action Control: Positive: Saliva and HCL+ saliva

Biuret test is a test which is utilized to indicate unhydrolyzed proteins. When there are peptides in a solution, a copper (II) ion forms violet-coloured coordination complexes in an alkaline solution. The biuret test can be utilised to analyse the concentration of proteins due to peptide bonds that occur with the same frequency per amino acid inside the peptide. In this experiment, the colour changed to purple to indicate the presence of protein. The pH was found to be 7, which is in the range of a healthy person’s pH (which is 7.4).Benedict`s solution is made up of alkaline copper sulphate and sodium citrate (blue in colour) (Danson and et al, 1996).

The gel piece with the lanes 7-10 was put in a 10 ml blotting buffer until western blotting. The gel piece containing the lanes 1-6 was then placed under UV-light or onto a transilluminator for the visualization of the fluorescent modification. Then the visualized gel was documented by taking a picture in Gene map program. Afterwards, the visualized gel was stained with Coomassie Brilliant Blue protein stain. Staining was done for 30 to 60 mins, within this time the staining solution was recycled after 15 mins.

The pKa of this unknown weak acid is 4.0 and the Ka is 1.0 x 10-4 mol dm-3 while the molecular weight is 166.67 g mol-1. It is closely related to the ascorbic acid with a pKa of 4.10 and a Ka of 7.9 x 10-5 with a molecular weight of 176.12 g mol-1. Therefore it can be concluded that the unknown acid is ascorbic acid. Titration technique is best suited for this experiment because the end point and equivalence point can be distinguished by the physical changes which are the colour change of the mixture. We are also able to better control and determine the volume of NaOH in the burette needed to neutralise HCI, CH3COOH and the unknown acid.

The phenol-red indicator helps to identify the bacteria. Upon viewing my results it was determined that my colonies did not ferment mannitol. This was easily observed because they remained translucent. The incubation times for all of the inoculated tests were for 48 hours (due to lab schedule, supposed to be 24 hours) and the temperature they were incubated at was at 37C. 37C is the optimal temperature to maintain the state of the agar as well as the ideal temperature for continued microbial growth to occur. My fourth and final test conducted to help identify my bacteria was an Oxidase test.

So the results were sulfur: positive, indole: Negative, and for medium: medium motility. And the results indicated that could be Klebsiella pneumoniae but also it could be Enterobacter aerogenes. To confirm the deduction of hat my bacterium could be Klebsiella pneumoniae I decided to do my fourth test. And the Urea Hydrolysis and if the results turn negative the bacterium will be Enterobacter aerogenes, or if it turns positive the bacteria will be Klebsiella pneumoniae.

After the loop cooled down, the loop was usedd to obtain a sample of the unknown mixture. This done by inserting the loop in the test tube of the unknown mixture. The loop was now ready to begin streaking; the plate was divided into four quadrants. Streaking was initiated into the first quadrant using a side-to-side swipe method. After streaking into the first quadrant, place the loop through the flame for 3-5second in order to reduce the amount of bacteria

Research Protocol – Monitoring of the Daphnia magna heart rate The experiments focused on the four treatments of nicotine, caffeine, ethanol, and double distilled water (placebo). 180 μL of each bioactive solution (nicotine was covered with foil, due to light sensitivity) and 120 μL of double distilled water were placed into labeled eppendorf tubes to dismiss cross-contamination, and were placed on ice to match the environment of the Daphnia to reduce any added stress on the Daphnia. One Daphnia was placed on the testing petri dish, and then all the excess pond water was removed with a transfer pipette.

Both strain A and B were positive and strand C was negative. There was a significant difference in E.coli strand C under sucrose compared to E.coli strain A and B. Strain A and B were both positive while strain C was negative.