Thermo Scientific protein quantitative product selection method

Thermo Scientific protein quantitative product selection method

Chromatography, electrophoresis, and immunochemistry are usually used to quantify protein before separation or analysis. Reagents for quantitative protein analysis by colorimetry are usually divided into two categories: one is indirect detection, which detects reduced copper ions after chelating with protein; the other is direct detection, which uses dyes that bind to protein , To detect the color change in the sample. Thermo Scientific BCA and modified Lowry protein quantitative analysis are based on copper ion chelation. ThermoScientific 660 nanometer and Coomassie (Bradford) protein quantitative analysis is based on the method of dye binding. These reagents are familiar, stable methods, and can provide consistent and reliable results. Overall, these methods represent the current state of the art in colorimetric detection and total protein quantification.
1. Selection of protein standards The best choice for reference standards is a pure, known concentration of protein that predominates in the sample. But usually this is impossible and unnecessary; all the experiments need is to estimate the total protein concentration in the sample. If the high-purity product of the protein of interest is not available or it is too expensive to use as a standard, the alternative method is to select a protein that needs to produce a very similar color response curve in the selected protein quantitative analysis experiment and Any laboratory can be used at any time. For daily protein quantitative analysis, bovine serum albumin (BSA) is a good protein standard due to its high purity, easy availability, and relatively cheap price. Although bovine gamma globulin (BGG) contains a mixture of several immunoglobulins, the color response curve produced by BGG is very similar to that of immunoglobulin (IgG), so when measuring antibody concentration, bovine gamma globulin is also A good standard.
2. Selection of protein quantitative analysis methods In order to be as convenient and practical as possible, protein quantitative analysis methods will not be specific to proteins (ie not affected by any non-protein components) or as sensitive to all types of proteins (ie not affected by proteins) The impact of component differences). Therefore, the successful use of protein quantitative analysis reagents includes the selection of the analysis method that is most suitable for the sample to be tested, the selection of appropriate standards, and the limitations of understanding and controlling methods.
When the total protein concentration in the sample needs to be determined, the appropriate protein quantitative analysis method must be selected first. Choosing the appropriate reagent among many alternative protein quantitative analysis reagents usually considers the compatibility of the method used with the sample to be tested. The purpose is to choose a measurement method that allows users to perform minimal operations and pretreatment on samples containing interfering substances. Each method has its own advantages and disadvantages. Because no one reagent can best determine protein in all environments, most researchers have multiple reagents for quantitative protein analysis in their laboratories. Our BCA protein quantitative analysis kit and Bradford protein quantitative analysis kit can complement each other, and provide two basic measurement methods for most samples. Various auxiliary reagents and improved versions of these two analytical methods are suitable for the needs of special samples.

Thermo Scientific Protein Quantitative Analysis Reagents Important Compatibility Important Incompatibility Protein and Protein Uniformity BCA Detergent Reducing Agent, Chelating Agent High BCA-Reducing Agent Compatible Detergent and Reducing Agent †† Chelating Agent Type High Trace BCA Removal Staining agent reducing agent, high chelating agent Lowry SDS Most detergent, reducing agent, chelating agent high 660 nanometer detergent and reducing agent; if using processing reagent, it can be compatible with Laemmli SDS sample buffer. Ionic detergent is low. Coomassie enhanced most of the reducing agent and chelating agent detergent. Coomassie most of the reducing agent and chelating agent detergent is low. † The total measured volume is 1 ml. The sample volume is at Carried out in a 1 cm cuvette. ‡ The total measurement volume is the sample volume at 200-300 microliters, and the detection is performed in a 96-well plate.
†† Typical amounts of cell lysis and protein buffer.