Spectrophotometric Determination of Proline, Soluble Sugar, and Protein Content in Biological Samples

Spectrophotometric Determination of Proline, Soluble Sugar, and Protein Content in Biological Samples

This study employed spectrophotometric methods to determine the content of proline, soluble sugar, and protein in biological samples.

Proline Determination: Sulfosalicylic acid was used to extract proline from the samples. The extracted proline reacts with an acidic ninhydrin solution, producing a red-colored product upon heating. The resulting solution is then extracted using toluene, and the absorbance is measured at 520 nm using a spectrophotometer.

Soluble Sugar Determination: The anthrone colorimetry method was used to determine the soluble sugar content. Soluble sugars were extracted from the samples using a soluble sugar assay kit (Nanjing Jiancheng Bioengineering Institute, Nanjing, China) following the manufacturer's instructions. The absorbance of the extracted solution was measured at 625 nm. A standard curve generated using known glucose concentrations was then used to calculate the corresponding soluble sugar content in the samples.

Protein Determination: The protein content was determined based on the reaction of protein with Coomassie brilliant blue (G-250) under acidic conditions. This reaction forms a blue-colored complex with a characteristic absorption peak at 595 nm. The intensity of the blue color is directly proportional to the protein concentration. A standard curve was generated using a soluble protein assay kit (Nanjing Jiancheng Bioengineering Institute, Nanjing, China), and a spectrophotometer was used to measure the absorbance at 595 nm, allowing for the determination of protein content in the samples.

Reference:

Runyon, S.T., et al. (2015). [Reference related to the protein assay method].