2',4',5',7'-tetraiodofluorescein, Disodium Salt

2%27%2C4%27%2C5%27%2C7%27-tetraiodofluorescein disodium salt has a wide range of uses. In the field of medical testing, it is often used as a diagnostic reagent. Because of its special optical properties, it can emit light and color under specific detection methods, helping doctors to accurately detect specific substances or cells in biological samples, providing a key basis for disease diagnosis.
In the field of analytical chemistry, this substance is an important indicator. In some titration analysis experiments, it can keenly indicate the reaction endpoint by color change, making the analysis results more accurate.
In scientific research experiments, it is also commonly used as a fluorescent marker. Scientists can connect it to target molecules, use its fluorescence properties to track molecular behavior, monitor intermolecular interactions, and help reveal microscopic mechanisms in organisms.
In the field of staining, 2%27%2C4%27%2C5%27%2C7%27-tetraiodofluorescein disodium salt also has outstanding performance. Whether it is biological tissue section staining or cell staining, it can clearly show the target structure or cell, which is convenient for researchers to observe and study under a microscope.

2%27%2C4%27%2C5%27%2C7%27 - tetraiodofluorescein, Disodium Salt is the disodium salt of tetraiodofluorescein, commonly known as erythrosine, which is a synthetic food pigment. The following are its physical properties:
Its appearance is red to reddish brown powder or granule, odorless. This substance is easily soluble in water, in a bluish red clear solution; soluble in ethanol, propylene glycol and glycerol, slightly soluble in ether, insoluble in grease. Good solubility in water, the solubility reaches 6.5% at 21 ° C, and the solubility increases to 21.6% at 100 ° C. Its aqueous solution is stable between pH 3-10, and it has good light resistance, heat resistance, acid resistance and salt resistance. However, its oxidation resistance and bacterial resistance are slightly weaker, and its stability in alkaline solutions is stronger than in acidic solutions. It does not decompose even when heated to 300 ° C. It has strong hygroscopicity and is extremely stable in dry state.
The color value of tetraiodofluorescein disodium salt is high, and the color is bright. The color is slightly different in different pH solutions. It is yellow-red when the pH value is about 5, and red when the pH value is about 8. These physical properties make it widely used in food, medicine, cosmetics and other industries to give products a pleasing color.

2%27%2C4%27%2C5%27%2C7%27-tetraiodine fluorescein disodium salt, this physical property is still stable. Looking at its chemical structure, the tetraiodine atom is connected to fluorescein and forms a sodium salt state. The iodine atom has high electronegativity, which can cause different charge distributions in the molecule. After the sodium salt is formed, the ionic bond makes the structure slightly stable.
In common environments, under normal temperature and pressure, if there is no strong oxidation or reducing agent, strong acid and alkali invasion, its chemical state can be maintained constant. However, light may cause slight changes. Because the intramolecular conjugated system is sensitive to light, light can cause electron transitions and cause slight structural changes.
Furthermore, humidity also has an effect. Although it is a sodium salt, the hygroscopicity is not strong, but it is placed in a place with high humidity for a long time, or the crystal form changes due to moisture absorption, which affects the physical properties. However, in general, in conventional storage conditions, such as dry, cool and protected from strong light, the chemical properties of 2%27%2C4%27%2C5%27%2C7%27-tetraiodofluorescein disodium salt can be maintained stable, and it can be used for many purposes without light deterioration.

2%27%2C4%27%2C5%27%2C7%27-tetraiodofluorescein disodium salt is widely used in many fields. In the context of medical testing, it is often used as a diagnostic reagent. Through specific chemical reactions, it can be combined with specific biomolecules, and with its own significant color characteristics, it helps physicians to clearly identify and accurately detect specific substances. For example, in immunoassay, it can acutely indicate the reaction of antigens and antibodies, providing a key basis for disease diagnosis.
In the field of scientific research, it is also an important experimental material. In cell biology research, it can effectively stain cells, helping researchers to clearly observe cell morphology, structure and distribution of specific organelles under a microscope, and gain insight into cell physiology and pathological states. In biochemical experiments, it can be used to track the metabolic pathways of biomolecules and help researchers gain a deeper understanding of complex biochemical processes in living organisms.
In the field of industrial production, it shows unique value in the printing and dyeing industry. With its own bright colors and good dyeing properties, it can make fabrics present rich and lasting colors to meet the public's demand for textile aesthetics. In the field of ink manufacturing, as an important colorant, it gives inks bright colors and excellent printing effects, and is widely used in various printed products, such as books, posters, packaging, etc., to enhance the visual appeal of printed products.

2%27%2C4%27%2C5%27%2C7%27-tetraiodofluorescein disodium salt, the preparation method is as follows:
To prepare 2%27%2C4%27%2C5%27%2C7%27-tetraiodofluorescein disodium salt, first take fluorescein as the starting material. Place an appropriate amount of fluorescein in the reaction kettle and add an appropriate amount of solvent. This solvent needs to be able to dissolve fluorescein well and not interfere with subsequent reactions, such as glacial acetic acid.
Then, slowly add an iodine source to the reaction system. The common iodine source can be a mixture of iodine elemental substance and potassium iodide, which can generate active iodine species that can participate in the reaction under acidic conditions. At the same time, add an appropriate amount of oxidant, such as hydrogen peroxide. Hydrogen peroxide in an acidic environment can promote the oxidation of iodine to a higher valence state of active iodine, thereby promoting the substitution reaction of iodine on the fluorescein benzene ring.
During the reaction, it is necessary to strictly control the temperature. The temperature should be maintained in a specific range, such as between 60-80 degrees Celsius. If the temperature is too low, the reaction rate is slow and time-consuming; if the temperature is too high, it may initiate side reactions and form impurities. Under continuous stirring, the reaction is carried out for several hours to make the reaction fully proceed. Monitor by TLC (thin layer chromatography) and other means until the raw material fluorescein is exhausted.
After the reaction is completed, cool the reaction solution to room temperature, and then slowly add an appropriate amount of sodium hydroxide solution dropwise The purpose of this step is to convert the 2%27%2C4%27%2C5%27%2C7%27-tetraiodofluorescein in the system to its disodium salt form. During the dropdown process, pay attention to the pH of the solution and control the pH to the alkaline range, about 8-9. After
, the reaction mixture is filtered to remove insoluble impurities. The filtrate can be distilled under reduced pressure to remove most of the solvent. Add an appropriate amount of organic solvent, such as ethanol or acetone, to the remaining concentrate. At this time, the 2%27%2C4%27%2C5%27%2C7%27-tetraiodofluorescein disodium salt will precipitate in solid form. The solids are collected by suction filtration and washed with a small amount of cold organic solvent to remove impurities. Finally, the resulting solid was placed in an oven and dried at low temperature to obtain a pure 2%27%2C4%27%2C5%27%2C7%27-tetraiodofluorescein disodium salt product.