0
What else can I help you with?
A diluted protein solution (1 in 100) has an absorbance of 0.558 at 280nm when measured in a 1cm path-length cuvette. Calculate the concentration in mgmL of the undiluted protein solutions (extinctio?
One needs the extinction coefficient in order to answer this question. Otherwise it cannot be answered properly.
Why absorbance should be taken in 750 nm in lowrys method?
Absorbance at 750 nm in Lowry's method is used because it corresponds to the peak absorbance of the copper-tyrosine complex formed during the reaction, ensuring accurate measurement of the protein concentration. This wavelength specifically targets the color change associated with the biuret reaction, enhancing the sensitivity and specificity of the assay.
Why is the total protein are measured at 595 nm in the Bio-Rad assay?
The Bio-Rad protein assay measures the total protein content in a sample at 595 nm because this wavelength corresponds to the absorption peak of protein-bound Coomassie Brilliant Blue dye. When proteins are present in the sample, they bind to the dye, causing a shift in absorbance at 595 nm, which is used to accurately quantify the protein concentration.
Would the concentration of a diluted protein shake with an absorbance value of 70mg ml be darker than a protein concentration of 15mg ml?
Yes, the diluted protein shake with an absorbance value of 70mg/ml would appear darker than the protein concentration of 15mg/ml. Higher absorbance values indicate a higher concentration of solute present in the solution, leading to a darker appearance.
Why do you use the wavelength with the maximum absorbance in spectroscopy?
Short answer:Using the maximum wavelength gives us the best results. This is because at the peak absorbance, the absobance strength of light will be at the highest and rate of change in absorbance with wavelength will be the smallest. Measurements made at the peak absorbance will have the smallest error.Long answer: It really depends on what is the largest source of error. Taking the readings at the peak maximum is best at low absorbance, because it gives the best signal-to-noise ratio, which improves the precision of measurement. If the dominant source of noise is photon noise, the precision of absorbance measurement is theoretically best when the absorbance is near 1.0. So if the peak absorbance is below 1.0, then using the peak wavelength is best, but if the peak absorbance is well above 1.0, you might be better off using another wavelength where the absorbance is closer to 1. Another issue is calibration curve non-linearity, which can result in curve-fitting errors. The non-linearity caused by polychromatic light is minimized if you take readings at either a peak maximum or a minimum, because the absorbance change with wavelength is the smallest at those wavelengths. On the other hand, using the maximum increases the calibration curve non-linearity caused by stray light. Very high absorbances cause two problems: the precision of measurement is poor because the transmitted intensity is so low, and the calibration curve linearity is poor due to stray light. The effect of stray light can be reduced by taking the readings at awavelength where the absorbance is lower or by using a non-linear calibration curve fitting technique. Finally, if spectral interferences are a problem, the best measurement wavelength may be the one that minimizes the relative contribution of spectral interferences (which may or may not be the peak maximum). In any case, don't forget: whatever wavelength you use, you have to use the exact same wavelength for all the standards and samples. See http://terpconnect.umd.edu/~toh/models/BeersLaw.htmlTom O'HaverProfessor Emeritus
Why acetone show absorbance at 280nm?
Acetone exhibits absorbance at 280nm due to the presence of its carbonyl group (C=O), which is associated with a peak in the ultraviolet-visible spectrum at that wavelength. The absorbance at 280nm is a characteristic feature of the electronic transitions within the molecular structure of acetone.
Why do protein have 2 absorbance peak at 280 nm?
Proteins exhibit two absorbance peaks around 280 nm primarily due to the presence of aromatic amino acids, such as tryptophan and tyrosine. Tryptophan has a strong absorbance peak near 280 nm, while tyrosine contributes a smaller peak at the same wavelength. The combined absorbance from these amino acids allows for the estimation of protein concentration in solutions, as they are key components in the protein structure.
A diluted protein solution (1 in 100) has an absorbance of 0.558 at 280nm when measured in a 1cm path-length cuvette. Calculate the concentration in mgmL of the undiluted protein solutions (extinctio?
One needs the extinction coefficient in order to answer this question. Otherwise it cannot be answered properly.
What is peak absorbance?
Peak absorbance refers to the wavelength at which a substance absorbs light most strongly. It is commonly used in spectrophotometry to determine the concentration of a substance in a solution by measuring the absorbance at its peak wavelength.
What wavelength is the peak absorbance for cobalt chloride?
The peak absorbance for cobalt chloride typically occurs around 550-600 nm.
How to calculate protein concentration from absorbance at 280 nm?
To calculate protein concentration from absorbance at 280 nm, you can use the Beer-Lambert Law. This law states that absorbance is directly proportional to concentration and path length. By measuring the absorbance of the protein sample at 280 nm and using the extinction coefficient of the protein, you can calculate the concentration of the protein in the sample.
What is the principle behind Quantification of DNA by reading its optical density at 260nm and 280nm?
The principle behind quantifying DNA by measuring its optical density at 260nm and 280nm is based on the fact that DNA absorbs light at these specific wavelengths. The ratio of the absorbance at 260nm to 280nm is used to assess the purity of the DNA sample, with a 260/280 ratio of around 1.8 considered indicative of pure DNA. By comparing the absorbance values at these two wavelengths, scientists can estimate the concentration and purity of DNA in a sample.
How do you find whether given sample is DNA or RNA?
A spectrophotometer can be used to know if a sample is DNA or RNA. DNA has an absorbance maximaat 260nm, whereas RNA has an absorbance maxima at 280nm. By looking at which one of these two wavelengths the sample is more excited, one can determine if the sample is DNA or RNA.
Why absorbance should be taken in 750 nm in lowrys method?
Absorbance at 750 nm in Lowry's method is used because it corresponds to the peak absorbance of the copper-tyrosine complex formed during the reaction, ensuring accurate measurement of the protein concentration. This wavelength specifically targets the color change associated with the biuret reaction, enhancing the sensitivity and specificity of the assay.
How can absorbance be utilized in determining protein concentration?
Absorbance can be used to determine protein concentration by measuring the amount of light absorbed by a protein sample at a specific wavelength. This measurement is then compared to a standard curve of known protein concentrations to calculate the protein concentration of the sample.
How the absorbance data correlates to the initial protein concentration in ug ml?
The absorbance data correlates to the initial protein concentration in ug ml in one way. It breaks down protein in the stomach by the action of the stomach acid.
Why is the total protein are measured at 595 nm in the Bio-Rad assay?
The Bio-Rad protein assay measures the total protein content in a sample at 595 nm because this wavelength corresponds to the absorption peak of protein-bound Coomassie Brilliant Blue dye. When proteins are present in the sample, they bind to the dye, causing a shift in absorbance at 595 nm, which is used to accurately quantify the protein concentration.
