Bromophenol blue is a light yellow to brownish yellow powder; It is easily soluble in sodium hydroxide solution, soluble in methanol, ethanol and benzene, slightly soluble in water (about 0.4g/100ml), and the maximum absorption wavelength is 422nm. It is a pH indicator. In the range of pH 3.0~4.6, the color changes from yellow to blue; It is also commonly used as an electrophoretic indicator dye. The electrophoretic migration rate in the gel is in the region of small molecules of nucleic acid or protein. When studying the interaction between human hemoglobin and various animal hemoglobin (abbreviated as interaction), it was accidentally found that bromophenol blue (BPB) can also interact with chicken hemoglobin in the process of cross electrophoresis, but this phenomenon does not exist between BPB and adult hemoglobin. BPB is different from hemoglobin. It is a low molecular compound. Its interaction with hemoglobin may be different from the interaction between hemoglobin in mechanism.
Examples of application of bromophenol blue are as follows:
1. A photochemical composite sensitive membrane for hydrogen ion recognition was prepared. The steps of the method are as follows:
1) First, dissolve 55g acrylamide in 20-30ml distilled water, filter it, then cool the filtered liquid to room temperature, then conduct suction filtration, wait for it to crystallize and dry naturally, vacuum dry it to obtain pure acrylamide;
2) Dissolve 10g of pure acrylamide, 0.04-0.05g of ammonium persulfate, 0.15-0.25g of N, N methylene acrylamide, 0.01-0.012g of cresol violet and 0.02-0.022g of bromophenol blue in distilled water, deoxidize with nitrogen and gradually heat them to obtain H+ionophore sensitive polymer based on cresol violet and bromophenol blue;
3) A high-speed centrifuge is used to rotate the polymer to form a photochemical composite sensitive film. The invention has simple process, low cost and good response speed, temperature characteristics and repeatability of the prepared sensitive film. It can effectively expand the sensitive range to hydrogen ions, and can be used to manufacture the sensitive part of the recognizer of the hydrogen ion photochemical sensor.
2. A compound protein powder with calcium supplement function is prepared, which comprises the following raw materials and weight fractions: almond cake accounts for 30-40% of the total mass; Acetone accounts for 1.5~2.5% of the total mass; The proportion of sodium bicarbonate solution in the total mass is 8-15%; Hydrochloric acid accounts for 1.5~2.5% of the total mass; Bromophenol blue accounted for 1.5~2.5% of the total mass; The proportion of vitamin D in the total mass was 12-18%; Calcium gluconate accounts for 15-20% of the total mass; Ethanol accounts for 1.5~2.5% of the total mass and distilled water accounts for 15~20% of the total mass. The invention uses almond cake as raw material, extracts with acetone and ethanol, filters and dries to prepare protein powder, and uses calcium gluconate as calcium supplement. The compound protein powder produced by using this method not only improves the sensory quality obviously, but also can greatly improve the use effect when used in combination with protein and calcium gluconate, which is suitable for middle-aged and elderly people with calcium deficiency.
3. Prepare a kit for predicting the efficacy of sulfonylureas, containing the following components:
(1) Red blood cell lysate;
(2) Leukocyte lysate;
(3) Protein precipitation solution;
(4) Nucleic acid storage solution;
(5) PCR reaction mixture (containing MgCl2, dNTP, PCR amplification primer and internal standard);
(6) DNA polymerase;
(7) Positive quality control;
(8) Negative control;
(9) Endonuclease buffer system;
(10) Restriction endonuclease;
(11) PCR water;
(12)10 × Sample loading buffer for electrophoresis: 0.25% bromophenol blue, 40% (w/v) sucrose aqueous solution. In this method, genomic DNA was extracted from biological samples, and the polymorphism of sulfonylurea receptor gene in individual biological samples was detected by polymerase chain reaction restriction fragment polymorphism (PCR-RFLP) analysis to predict the efficacy of sulfonylurea drugs.
Synthetic bromophenol blue:
1. Dissolve phenol red in glacial acetic acid, add bromine solution in glacial acetic acid under stirring, stir for a few minutes, pour it into 60 ℃ hot water, cool it to room temperature, and place it overnight. Filter, wash the filter cake with glacial acetic acid and benzene in turn, and air dry to obtain bromophenol blue.
2. Dissolve phenol red in glacial acetic acid, heat it to boiling point, drop solution of bromine dissolved in glacial acetic acid, filter when yellow solid is separated, wash free bromine with acetic acid, and dry it in air to obtain crude product. Use glacial acetic acid or acetone and glacial acetic acid mixed solvent to recrystallize to obtain pure bromophenol blue.
3. Dissolve phenol red and bromine in acetic acid to prepare solution. First, heat the phenol red acetic acid solution to boiling point, then slowly add bromine acetic acid solution under stirring: when the phenol red reaction is complete and the yellow crystals are no longer separated, cool and filter. After washing off the free bromine in the crystal with a small amount of acetic acid, recrystallize it with acetic acid or acetone acetic acid, and dry it in air to obtain pure bromophenol blue.