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Part A: Detailed steps for preparing wash buffer, elution buffer, and 0.1 M sodium phosphate buffer with pH 6.24.
Part B: Instructions for handling samples, filtering egg white, and conducting centrifugation steps for protein purification.
Part C: Constructing a standard curve and conducting protein assays with necessary steps and dilutions.
Part D: Preparation of a cell wall suspension, labeling test tubes, adding lysozyme, recording absorbance readings, and calculating enzyme activity.

Part A The wash buffer was prepared by calculating the required amount of glycine and adding it to around 70% of the total volume of distilled water. Once dissolved, the solution underwent titration w

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Question: paraphrase. dont use first or third person. Part A For the wash buffer, the required mass of glycine was calculated and added to about 70% of the final volume of distilled water. After proper dissolution, the solution was titrated with a compatible acid to achieve pH 10. Then, the volume was adjusted to the correct level with distilled water.For the elution buffer, sodium chloride was first added to the desired concentration, followed by the calculated amount of glycine. Again, these were dissolved in approximately 70% of the final volume of distilled water. After titration to pH 10, the volume was adjusted to 50 ml with distilled water.For the 0.1 M sodium phosphate buffer with a pH of 6.24, the necessary calculations were carried out to determine the mass of sodium phosphate required. Following the procedure, the sodium phosphate was dissolved in about 70% of the final volume of distilled water. Then, the solution was titrated to the target pH and the volume was adjusted to 100 ml with distilled water. Part B The most essential principle to remember was to keep all samples COLD at all times, so ice was placed in a container in which the samples were to be placed.10 ml of pre-swelled activated CM-Sephadex was obtained and placed in a CLEAN 15 ml centrifuge tube. It was gently swirled, and any broken beads of gel found in the buffer above the gel were poured off. More glycine pH 10 buffer was added to the gel and gently stirred.An egg was obtained, and the white was separated from the yolk. The volume of the egg white obtained was measured and recorded. The egg white was then filtered through a double layer of cheesecloth by gently pressing the cheesecloth over the rim of a 100 or 150 ml beaker, which was placed in an ice bath.Each group transferred 3 ml of the egg filtrate to a clean 15 ml centrifuge tube and diluted it 1:5 (15 ml total volume) with glycine (pH 10) buffer. The volume was measured, and an A280 reading was taken. Two 1.5 ml samples were saved and labeled as Sample C (crude) and stored on ice.The clear buffer layer of the 10 ml of pre-swelled CM-Sephadex medium was removed. The filtered egg white was added to the CM-Sephadex, divided into two equal samples (approximately 12.5 ml per tube), and gently swirled for 10 minutes. The mixture was then centrifuged at approximately 500 rpm for 5 minutes.The supernatant was removed, and its volume was recorded. Its absorbance at A280 was measured using quartz cuvettes. Two 1.5 ml samples were taken from the supernatant fraction, labeled as W1 (wash 1), and placed on ice. The rest of the supernatant was discarded, but the CM-Sephadex was kept.15 ml of wash buffer (glycine pH 10 buffer) was added to the resin, gently swirled, and centrifuged as before to wash off any unbound proteins. The volume of the wash was measured, and its A280 was recorded. Steps 12 and 13 were repeated until the supernatant reading was near 0 at A280. A sample of this last wash (2 x 1.5 ml) labeled as W2 was saved on ice.10 ml of wash buffer was added to the CM-Sephadex, and the CM-Sephadex was gently poured down the side of a glass-stirring rod into the column. Buffer was allowed to slowly move out of the column below, and all the CM-Sephadex was ensured to fit into the column. The column was not allowed to run dry.Once the column was packed, any buffer from above the resin was removed, and 20 ml of elution buffer (0.5 M NaCl, 0.1M Glycine buffer pH 10) was added. 5 ml elution (EL) fractions were collected and placed on ice. Elution was continued until A280 came down to 0, adding more elution buffer if necessary.The high protein containing fractions were pooled together, and the volume was measured. Two 1.5 ml aliquots were kept on ice, labeled as the EL fraction.All centrifuge tubes (C, W1, W2, and EL) were placed in the freezer for next week’s practical.For results, a chromatography was needed, which is a graph of absorbance readings of all samples collected. The positions of C, W1, W2, and EL were indicated on the graph. Part C A standard curve was constructed from duplicate assays between 0 and 0.5 mg/ml of BSA protein. An individual standard curve was prepared using BSA and distilled water to ensure 2 ml of protein solution per assay.The standard curve was performed simultaneously with the protein sample analysis using the following method. It was noted that C, W1, W2, and EL samples needed to be diluted 100x before conducting the assay. Each sample was measured in duplicate. For each protein assay, 1 ml of the diluted sample was required. Reagent A (0.9 ml) was added to 1 ml of protein solution, including standard curve BSA dilutions as well as C, W1-2, and EL samples. The mixture was heated at 50 ºC for 10 minutes. Subsequently, the solutions were cooled in running tap water to room temperature, and then reagent B (0.1 ml) was added. The solutions were allowed to stand at room temperature for another 10 minutes.Following this, reagent C (3 ml) was added with immediate thorough mixing to ensure complete mixing within 1 second. The solutions were heated again at 50 ºC for 10 minutes. After cooling, the absorbance was read at 650 nm.All values were recorded neatly in a tabular form, and protein concentration for each sample was calculated from the standard curve, taking into account the dilutions. Part D Using 0.1 M Na phosphate (pH 6.24) buffer, a cell wall suspension was prepared at a concentration of 0.2 mg of cell wall per ml of phosphate buffer. This suspension was provided.To begin the experiment, 7 test tubes were labeled as Blank (B), C, W1, W2, EL, Ctrl, and commercial lysozyme. Each test tube contained 2.8 ml of the cell wall suspension and 0.2 ml of buffer. The absorbance reading for each tube was recorded after preparing.The spectrophotometer was set to 450 nm, and a blank reading was taken using plain phosphate buffer.0.2 ml of lysozyme-containing samples (C, W1, W2, EL, Ctrl, and commercial lysozyme) was added to each tube, and the tubes were quickly covered with Parafilm and gently mixed. Timing was initiated as soon as the lysozyme was added.The tubes were then placed in the spectrophotometer, and absorbance readings were recorded at 5 to 10-second intervals for approximately 2 minutes, extending the time if the absorbance was still decreasing.All values were recorded neatly in a tabular form.The Abs450 versus time in minutes was plotted, and the slope (Abs450 change per minute) was determined, correcting for any blank rate if present.One unit of lysozyme activity was defined as the amount of lysozyme that produces a 0.001 Abs450 change per minute.Finally, the enzyme activity (Units/ml) was calculated based on the determined slope and the definition of one unit of lysozyme activity.

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Part A For the buffering solution in the washing process, the necessary glycine weight was computed and integrated into around 70% distilled water final volume. This led to its complete dissolution. Afterwards, it was titrated using a compatible acid until pH 10 was achieved. The final volume was then adjusted using distilled water. For the elution buffer, sodium chloride concentration was first established. This was followed by the integration of the computed glycine amount. As with the previous buffer, both substances were dissolved in approximately 70% of distilled water final volume. After attaining pH 10 through titration, the volume was fine-tuned up to 50 ml using distilled water. As for the 0.1 M sodium phosphate buffer at pH 6.24, essential calculations were done to know the required sodium phosphate mass. As before, this sodium phosphate was dissolved in around 70% of distilled water final volume. After attaining the target pH through titration, the volume was adjusted up till 100 ml with distilled water. Part B The fundamental guideline to recall was that samples were always kept cold. Therefore, ice was put in a container where the samples were to be situated. From the pre-swelled activated CM-Sephadex, 10 ml was acquired and placed in a pure 15 ml centrifuge tube. This tube was carefully swirled, where any broken gel beads found in the buffer located above the gel were discarded. Extra glycine pH 10 buffer was incorporated into the gel and stirred gently. An egg white was separated from the yolk. The quantity of egg white obtained was measured and noted. Part C A standard curve was traced from duplicate assays. Each standard curve was prepared using BSA with distilled water to ensure 2 ml of protein solution per assay. Assays were done simultaneously with the protein sample analysis using this process. It was observed that C, W1, W2, and EL samples were diluted 100 times before putting them into the assay. Each sample was conducted in duplicate. Part D With 0.1 M Na phosphate buffer at pH 6.24, a suspension of cell wall was created at a concentration of 0.2 mg of cell wall per ml of phosphate buffer. This arose suspension was offered. To initiate the experiment, a total of 7 test tubes were marked. The labeled test tubes; Blank, C, W1, W2, EL, Ctrl, and commercial lysozyme, were all incorporated with 2.8 ml of the cell wall suspension as well as 0.2 ml of buffer. The absorbance reading for each tube was noted after each preparation. The quantity of lysozyme activity was then defined as the lysozyme amount that results in a 0.001 Abs450 change per minute. Finally, the enzyme activity was evaluated based on the slope and the definition of one unit of lysozyme activity.

Answered by gpt-4

March 11, 2024, 12:51 a.m.

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This article was generated in part by one of OpenAI’s large-scale language-generation model, answering user mahlatsi's question. Images were generated with OpenAI's AI model, DALL·E 2. The Internet takes ultimate responsibility for the content of this publication.
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Published: Monday, March 11, 2024

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