Sds Page (Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis)

This Lab Report is an analysis of the results of a two-part experiment. In the first part, we used a gel filtration column to separate the components of a mixture composed of protein and non-protein molecules. By doing so we hoped to obtain fractions that contained single components of the mixture, while also gaining insight into the relative molecular weight of each component compared to each other. We would then plot these fractions onto nitrocellulose paper in order to determine which fractions had protein. In the second part, we would use the fractions which we had determined had protein to conduct an SDS-PAGE. By doing so we hoped to determine an estimate on the molecular weight of the proteins present in each fraction by comparing it to a tracker dye composed of a variety of molecules of differing molecular weight.

Protein Assay: The Pierce BCA Protein Assay (Thermo Scientific) is a detergent-compatible formulation based on bicinchoninic acid (BCA) for the colorimetric detection and quantitation of total protein concentration. A series of standard solution of Bovine Serum Albumin (BSA) ranging from 0-2000 µg/ml was prepared from a stock solution of 2 mg/ml BSA. 25ul of diluted crude (1:500, 1:250), desalted (1:100, 1:50), and 6 peak fractions from cibarcon blue column (1:10, 1:5) were loaded in microplate along with 175ul of BCA working reagent. Microplate was incubated for 30min at 370C and then the absorbance was measured at 562nm.

Colorimetric assay is a process of determining a concentration of a solution based on absorbance of light. The purpose of this lab is to determine if the Bradford assay is an accurate way to determine an unknown concentration of two samples of protein. The Bradford assay is done by measuring wavelength of light passing through a cuvette filled with Bradford dye and concentrations of PBS and proteins. After the cuvettes are mixed they are placed into a spectrophotometer to measure wavelength. The wavelength given will be used to plot a standard curve based on concentration (x-axis) and wavelength (y-axis). The standard curve is then used to measure an educated guess on the concentrations of unknown protein concentrations. We hypothesized that if we use the Bradford assay and colorimetric spectrophotometry we can determine an accurate concentration of two unknown concentrations of proteins. The results of this lab failed to reject our hypothesis based on accurate measurements of protein concentrations. The standard curves are drawn with a linear increasing slope. The Bradford assay is an accurate way to demine the concentration of an unknown concentration.

Salting out is the first isolation technique carried out for this lab. This isolation technique separates the Rubisco based on solubility. The method of salting out requires an addition of salt such as ammonium sulfate to the solution containing protein Rubisco to allow precipitation (Duong-Ly & Gabelli, 2014). The additional of ammonium sulfate to the Rubisco

Figure 1 contains gel electrophoresis for protein samples. The lanes were labeled from 1 to 10 from the right to the left. Lane 1 contained the ladder fragment. Lane 2 contained the filtrate. Lane 3 contained the S1 sample. Lane 4 contained the P1 sample. Lane 5 contained the P1 medium salt sample. Lane 6 contained the P1 high salt sample. Lane 7 contained the S2 sample. Lane 8 contained the P2 sample. Lane 9 contained the P2 medium salt sample. Lane 10 contained the P2 high salt sample.

1. In the cell bio lab, we use company manufactured gels, however you can make you own polyacrylamide gels. List all of the ingredients found in an SDS-PAGE gel. Which ingredients are responsible for polymerizing the solution? How does the percentage of acrylamide effect the migration of proteins (ex: 4% gel vs. 18% gel)?

Having removed the detergent, the protein will refold. As shown by the Anfinsen experiment the polypeptide sequence determines the folding and therefore the three dimensional structure. As the polypeptide sequence is unaltered refolding can occur through the process of nucleation aggregation and compaction. In order to test that the protein was no longer denatured, the absorbency of the solution at 412nm could be measured and compared with the graph in figure 1 above, it should match the plot of standard ovalbumin in the absence of SDS.

The homogenates provided were made by homogenizing tissues in a sucrose phosphate buffer in a 1:20 ratio. The protein concentration in bovine cells was measured by diluting the homogenate with a 1:5 ratio; 50 microliters of homogenate and 200 microliters of water. Then 5 known protein concentration samples which were 0.4, 0.8, 1.2, 1.6, 2.0 mg/ml of bovine serum were used to determine absorbance with a spectrophotometer. Two additional samples were made; one was blank and the other was for the specific homogenate sample. Then 3 microliters of bradford assay reagent, which indicates the amount of protein present

Western blotting - In Western blotting first, the macromolecules have to be separated via gel electrophoresis. The molecules now separated by electrophoresis are blotted onto either a nitrocellulose or a polyvinylidene difluoride (PVDF) membrane (a second matrix). To inhibit the binding of nonspecific antibodies to the membrane surface it is subsequently blocked. Then a complex is formed (a probe) from the protein that was transferred and an enzyme linked with an antibody. The enzyme is supplied a substrate then the 2 together should create a product e.g. chromogenic precipitate that can be detected. Detection methods with most sensitivity use chemiluminescent substrate because light is a by-product of the reaction between the substrate and the enzyme. The output of the light can be measured using a CCD camera or on the other hand, antibodies that have been tagged with fluorescents that are detected with a fluorescence imaging system can be used (Thermo-Fisher Scientific 2015).

BI532: Skills for Bioscientists 2 Mini Project 2 report Effect on the velocity Alcohol Dehydrogenase on different alcohols under different conditions Abstract The effect on the velocity of Alcohol dehydrogenase producing an acetaldehyde was measured under different conditions to analyse the properties of the enzyme as well as the concentration the enzymes have the best rates. The velocity of alcohol dehydrogenase was measured against different substrates such as ethanol, propanol and propan-2-ol and using spectrophotometry at a wavelength of 340nm. While the enzyme velocity of ethanol production was high, propan-2-ol did not cause any changes the rate of acetaldehyde production. The amount of ethanol, which was the most reactive substrate, that reacted with the fastest rate was then calculated

Our first step was that we boiled the samples, A&M Std , & Kaleidescope Std. for 5min. in water bath, then we loaded the samples into the wells following the guide given which was as follows: 1- 10 ml of laemmli buffer, 2- 10 ml of molecular weight, 3- 10 ml of salmon, 4- 10 ml of tilapia, 5- 10 ml of catfish, 6- 10 ml of shrimp, 7- 10 ml of actin and myosin, and 8- 10 ml of the laemmli buffer. To load each sample, we used a P-200 (yellow) micropipette tip to withdraw 10 ml of each protein sample from its tube and gently transferred it into the designated well. After loading all samples, on both of the gels we then placed the lid on the tank, and insert the leads into the power supply, matching red to red and black to black. We ran the gel for 45 minutes at a constant voltage of 115V. When the gels were finished running, we discarded the buffer from the inner chamber, we released the cams, and removed the gel cassettes from the assembly. We laid each gel cassette flat on the bench with the short plate facing

SDS (sodium dodecyl sulphate) is a chemical agent that is used to denature protein molecules by straightening the polypeptide chain. Disulphide bonds are found in the tertiary structure of proteins and would not react if the protein remained folded. Without SDS, there would not be any thiol groups

If we have down SDS-Page, the purification could have show proteins based purely on molecular weight, because the charges would be neutralizes. SDS-Page is also known under denaturing conditions because it makes sure that even proteins with different conformations do not migrate through the gel any faster than a different protein. The higher molecular weight would migrate to the bottom more quickly than a lower molecular weight protein. SDS-Page could have shown the general molecular weights in the bands of LDH.

In this experiment 5 kDa and 10 kDa PEGs were used coat the lysozyme and the reaction profile was assessed using SDS-PAGE. Sodium Docecyl Sulphate (SDS) is a negatively charged detergent which coats the amino acids with in the proteins. Therefore there will be a net negative charge on the protein which defies its native charge. When placed within an electric field causes migration of the protein towards the cathode. Protein passes through PAGE gel has pores which causes size based separation.

Agarose gel electrophoresis is a method of gel electrophoresis used in biochemistry, molecular biology, genetics, and clinical chemistry to separate a mixed population of DNA or proteins in a matrix ofagarose. The proteins may be separated by charge and/or size