Bradford protein assay

About: Bradford protein assay is a research topic. Over the lifetime, 635 publications have been published within this topic receiving 239107 citations.

[Screening of Bacillus sp. strains producing thermostable alpha-amylase].

Abstract: Fifteen thermostable alpha-amylases have been obtained as a result of screening of 76 Bacillus sp. strains, isolated from different natural substrates. They have shown 30-100% of their activities after 60 min of incubation at 100 degrees C. Seven thermostable a-amylases demonstrated 100% of their activities after 60 min of incubation at 100 degrees C. These enzymes showed maximal activities at pH 9.0 and exhibited 10-30% of activities at pH 11.0 and 12.0. These properties make them promising for future research and possible practical use. In this paper we have proposed a modified iodometric method for measurement and calculation of alpha-amylases activity. The influence of ammonium sulfate on protein concentration measurement by Bradford method was demonstrated and a necessity of dialysis after precipitation with ammonium sulfate was proposed.

High-sensitive trace protein assay by argentation

Abstract: PROBLEM TO BE SOLVED: To provide an assay capable of high-sensitively and easily determining trace amounts of urinary protein in large numbers of specimens without using an immunological method. SOLUTION: A silver colloid is formed in a stain solution by preliminarily reacting a silver ion with a reducing agent comprised of ferrous sulfate. A protein in a cellulose acetate film can be determined using a method for combining the protein with the silver colloid to stabilize it. A certain amount of the specimen is spotted directly on the cellulose acetate film in a dry state without buffering. The protein in this state is fixed by sulfosalicylic acid and trichloroacetic acid, and then well cleaned by a diluted acetic acid solution. After the cleaning, the protein is stained with the argentation solution.

The Determination of the Protein Content in Food

Abstract: According to the current standard of Determination of Protein Content in Food GB/T5009.5-2003 in China,there are two methods to determine the protein content.They are Kjeldahl method of nitrogen determination and Dumas method.Both of the two ways determine the nitrogen content by nitrification firstly and then calculate the protein content according to the conversion coefficient between the nitrogen and protein.If such high nitrogen content chemical substance as Melamine is added to the food,the protein content will be higher accordingly.In this peper,four direct determination methods were introduced including Bradford method,Biuret method,Lowry method and ultraviolet absorption spectrometry.These methods are more precise to determine the protein content in food than Kjedahl method which often overstates the protein content due to adding the high nitrogen-containing substances.

Preliminary Study of Buffer Ratio in Protein Extraction from Placental Cotyledons of Kedah-Kelantan Cattle

Abstract: Protein extraction is a preliminary step of protein purification which mainly focus on maximization of total protein yield. The heterogeneous properties cause diversification of protein; therefore, there is no absolute protocol in protein extraction. The ratio of buffer gives different protein concentrations in different types of mammalian tissues, and this condition leads to the study of optimization of buffer ratio to obtain a better total protein yield. The objectives of this study were to compare the total protein yield based on three different ratios of buffer used. The phosphate buffer saline (PBS), radioimmunoprecipitation assay (RIPA) buffer, and RIPA buffer with the addition of protease inhibitor (Pi) were used with the ratios of 1:1, 1:3, and 1:5. Fetal cotyledons removed from the placenta have undergone mechanical disruption, incubation, sonication, and centrifugation. The supernatant was retained and quantified with Bradford assay to determine the total protein yield based on the standard curve of bovine serum albumin (BSA). There was a statistically significant different between buffer ratio (p<0.5) in RIPA and RIPA with addition of protease inhibitor buffers. RIPA buffer with the ration of 1:1 gave the best total protein yield (194.880±15.089 mg/g). As a conclusion, there was a significant interaction between buffer types and have greatly enhanced the total protein yield obtained from placental cotyledons of Kedah-Kelantan cattle.