Bradford Assay Lab Report

Make sure to use the same type of cuvette to keep the width consistent and to prevent any experimental error from arising. Obtain 5 of the same type of cuvettes and pre-rinse them thoroughly. Label them numbers one through five in increasing molarity. Then, fill each of the cuvettes with one of the five solutions you created back in Part A. We will first examine the solution that exhibits the highest concentration or molarity. Make sure to wipe the outside of the cuvette with a Kimwipe before placing into the SpectroVis Plus device. Observe the graph that is generated and make sure to take note where the maximum absorbance takes place.

Often times on many products the nutritional values do not add up. The consumers receive the product believing that the nutritional value is correct when in fact it is the opposite. Because consumers are, on various occasions, being deceived by the manufacturers, this experiment was done to test to see if the protein in commercially available products is correct. A spectrophotometer was used to measure the concentration of the molecule that was being investigated. A colorimetric indicator was added to the standards, and a graph was formed. The graph was used to determine the mathematical relationship between concentration and absorbance. In this experiment three product’s protein content (whole milk, muscle milk, and protein shake) were tested. The milk and muscle milk content for protein was approximately right, but the protein content for the protein shake was wrong. The whole milk had a final concentration of 41 mg/ml, protein had a final concentration of 34 mg/ml, and muscle milk had a final concentration of 70 mg/ml.

15) Obtain the boiled chloroplast suspension, mix, and transfer 3 drops to cuvette 4. Immediately cover and mix cuvette 4. Insert it into the spectrophotometer's sample holder, read the percentage transmittance, and record it in Table 4.4. Replace cuvette 4 into the incubation test tube rack. Take and record additional readings at 5, 10, and 15 minutes. Mix the cuvette's contents just prior to each readings. Remember to use cuvtte 1 occasionally to check and adjust the spectrophotometer to 100% transmittance.

In this investigation concentration of protein was to be found using the concentration of a known protein( already labeled) by measuring the concentration of protein in milk and the absorbance of light. It is hypothesized that the protein that will be tested will be the same as the already labeled one. The outcome from the lab shows that the protein that was used did not respond the same as the already labeled one known from the standard curve, therefore rejecting the hypothesis.The results prove the hypothesis as incorrect because the proteins concentration were different when the concentration was calculated and all had a high percent difference.

Next, we took initial absorbance readings in the Spec20 at an absorbance rate of 600 nm as well as an initial color reading. Then placed one sample under red, blue, green, or white light illuminators, and one sample in the dark. The cuvette placed under the white light acted as our positive control, and the cuvette placed in the dark acted as our negative control. We took absorbance readings of each cuvette every 5 minutes until we had four readings. After the fourth and final absorbance reading, we also took a final color reading.

Incorporation of assay controls included setting up a spectrophotomer and running the chart recorder with a full-scale deflection before the start of the assay. The set recorder had a corresponding value of 1 for the change in the absorbance. Therefore, prior testing was done to observe whether a change occurred in the readings. This helped to indicate that the results were valid, as they could have been affected by a fault during the setting up of the spectrophotometer. On the other hand this was considered as one of the controls for the experiment. Nevertheless, a new cuvette had to be used for each assay.

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.

The absorbance is measured using a Plate reader and a Standard curve is generated. Also, the different types of pipetting techniques are assessed in this Assay.

This paper will focus on some important nutrients that are important for general health: fiber and protein. My personal daily intake will be analyzed to determine what foods are providing the right type of proteins and fiber, and how food consumption might be adjusted to provide for a healthier nutrient intake. It is important to state at the outset that the nutrient intake that is being used for this analysis is only for a one-day period. However, it will provide some insight into my eating habits and how those habits might be improved from a scientific standpoint.

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.

concentration, record the absorbance readings at a fixed wavelength, and plot the absorbance vs. concentration data. The wavelength of 520 nm was selected for experiment Part

Then each tube was placed in the centrifuge at the maximum speed for 2 minutes (0 BAS/100%T). This step was done so that the supernatant is separated from the pellet, so that the supernatant would be able to be extracted for further testing. 1 mL of each solution (12) was transferred into each cuvette, and then placed in the spectrophotometer. The absorbance was read at 440 nm and recorded. This step was done so that we can find out the absorbance of the different samples.

A spectrophotometer’s purpose is to use colors of the light spectrum to determine the concentration of light absorbing molecules in a solution. (p.59) In this particular lab, our mission was to determine the protein concentration and the standard curve of the unknown sample of BSA. This, by preparing five dilutions of the unknown solution of BSA together with other known concentrations, and then experimenting by observing how the concentrations were passed through the spectrophotometer. The outcome resolved in the absorption levels being decreased, and this

After that, we placed our solutions in the spectrophotometer one by one, which we wiped with tissue paper and carefully inserted because they are fragile. While doing this, we recorded our results of the absorbance. Prior to adding our solution in the spectrophotometer, we wrote down the reading of the spectrophotometer when we tried to

To create the standard curve we used the spectrophotometer to calculate the absorbance of light and we used that variable on the y-axis. Then we took the given starch concentrations of the tubes and used them on the x-axis. Finally we plotted our points and used the finalized standard curve to determine the starch concentration in our controlled and treated experiments. The purpose of the standard curve is to show the relationship between the absorbance of light in the spectrophotometer and the concentration of starch in the tubes. With the use of the standard curve, it is possible to find the concentration of starch by taking the reading off of the spectrophotometer and finding it on the y-axis.