While Lowry method showed reproducible results for more than 2 months after sample storage at -20 C, Bradford method that has been shown to significan

Bradford Bradford method is based on the method of noncovalent binding of the anionic form of dye Coomassie Blue G-250 with the protein. Especially the dye reacts with arginine residues, one positively charged side chain, and light interaction is also observed with basic residues (histidine and lysine) and aromatic residues (tyrosine, tryptophan and phenylalanine). In the absence of protein, the dye-reagent is a red light, and the binding protein, a blue color with absorption maximum at 590 nm

Bradford exam that is very popular because of fast (5 minutes) and with one additional dye reagent to the sample. Offer non-linear calibration curve of the concentration of A590-20 in the 0.2-mg of total protein in the sample container volume of 20 ml (10-1000 mg / ml). Negative deviation from linearity occurs with this method because the method of Lowry and Smith. Assay in Bradford, because of the curvature in the free dye dilution high protein concentration and a better estimate of linearity can be achieved by A595-A465 to the concentration of dye exhaustion must be considered.

Bradford and the Lowry method that compared to protein in the sample count, the membrane fractions. While Lowry method showed reproducible results for more than 2 months after sample storage at -20 C, Bradford method that has been shown to significantly underestimate membrane protein, even after treatment with basic or surfactants, with the lower estimates, the long storage of samples. Tissue homogenate from rat brain was tested by the method Bradford initially showed 52% of the protein with the Lowry method, after 14 days the memory, this value has decreased to ~ 30%. Because membrane lipids
Phospholipids and total protein assay-Smith, membrane proteins must be quantitated by Lowry method, or by the ninhydrin method new.