Analysis of common problems in the application of sodium alginate in biochemical reagents

Editor:Sodium alginate　　　　Source:Sodium alginate manufacturer　　　　2017-05-28 14:57

Sodium alginate is a by-product after extracting iodine and mannitol from kelp or Sargassum of brown algae, and its molecule is composed of β -D- mannuronic acid (β -D-mannuronic, m) and α -L- guluronic acid (α -l -L-guluronic, g) press (1→ 4) key connection, which is a kind ofNatural polysaccharideIt has the stability, solubility, viscosity and safety required by pharmaceutical excipients. Sodium alginate has been widely used in food industry and medicine.
　　　　Sodium alginate is derived frombrown algagenerickelporsea grapeMiddle extractioniodineandmannitolSubsequentby-productIts molecule consists of β -D- mannuronic acid (β -D-mannuronic, m) and α -L- guluronic acid (α -l -L-guluronic, g) press (1→ 4) key connection. The aqueous solution of sodium alginate has high viscosity and has been used as food.Thickener、stabilizing agent、emulgatorWait. Sodium alginate is a non-toxic food, which was included in the United States Pharmacopoeia as early as 1938. Sodium alginate contains a lot of — COO－-,which can show polyanionic behavior in aqueous solution and has certain adhesion, can be used as a drug carrier for treating mucosal tissue. Under acidic conditions, — COO－-into — COOH，ionization degreeWhen decreasing, the hydrophilicity of sodium alginate decreases, the molecular chain shrinks and the pH value increases, — COOH group dissociates constantly, and the hydrophilicity of sodium alginate increases and the molecular chain stretches. Therefore, sodium alginate has obvious pH sensitivity. Sodium alginate can quickly form gel under extremely mild conditions, when Ca2+, Sr2+ and so on are present.cationWhen it exists, Na+ on G units reacts with divalent cations, and G units pile up to form cross-linked network structure, thus forming hydrogel. Sodium alginate formationgelMild conditions, which can avoid sensitive drugs, protein,cellandenzymeInactivation of such active substances. Because of these excellent characteristics, sodium alginate has been widely used in food industry and medicine.　
　Qingdao Nanshan biology science and technology co., ltdSpecializing in the production of sodium alginate for decades, seaweed is an important organic compound with the most existence and widest distribution in nature. Sodium alginate is a hydrophilic polysaccharide extracted from kelp, a marine algae plant, which is almost odorless and tasteless. Carbohydrate is the main source of energy needed by all organisms to maintain life activities. Carbohydrates are not only nutrients, but also some have special physiological activities. Today, Hongjie Algae Xiaobian tells us about the common problems of sodium alginate in the application of biochemical reagents.

　　Sodium alginate: Carbohydrate, also known as carbohydrate, is an important organic compound with the most existence and the widest distribution in nature. Sensitive to moisture, slowly soluble in water to form a viscous colloidal solution, insoluble in ethanol, ether, chloroform and acids with pH below 3. The solution does not condense when heated. The pH value of 1% aqueous solution is 6-8, and the viscosity is stable when the pH value is 6-9, and the viscosity decreases when it is heated above 80℃. Its use: biochemical research. It can be used as stabilizer, thickener, artificial semi-permeable membrane and mordant.

　　Frequently asked questions about the application of biochemical reagents:

　　reagent blank

　　1 > Narrowing of linear range: the high value is not high. Reason: The amount of active ingredients in the production of reagents is insufficient; The stability of reagent components is poor. 1.2 Decreased sensitivity: the slope of the enzymatic reaction speed curve decreases, and the determination results have serious systematic errors. Cause: The concentration of reagent substrate is insufficient. 1.3 phenomenon of high low value: the change curve of reagent blank (absorbance VS time) fluctuates obviously. Cause: the reagent itself is unstable and decomposes itself; The purity of tool enzyme is not enough, and the content of miscellaneous enzyme exceeds the limit, which leads to interference.

　　2 > sample information

　　The hemolysis, hyperlipidemia and jaundice of the sample will interfere with the determination results by non-chemical reactions. Therefore, according to the spectral absorption characteristics of hemolysis, lipid turbidity and jaundice, the dual-wavelength or multi-wavelength detection mode should be adopted, and the influence caused by hemolysis, lipid blood and jaundice should be deducted from the result calculation to reduce the interference degree.

　　3 > determination range

　　Each analyte has a measurable concentration or activity range. If the sample results exceed this range, the analyzer will display a hint that the results are out of range. Indicates that the reagent has deteriorated, and the qualified reagent should be replaced.

　　4 > substrate depletion

　　When using continuous monitoring method and two-point method to measure enzyme activity, if the enzyme activity is very high and the substrate is nearly exhausted, the absorbance will rise or fall beyond a certain absorbance change range, and the absorbance during the monitoring period will deviate from linearity, making the determination result unreliable.

　　5 > Pre-activation of enzyme

　　Some enzymes in serum, such as CK, are easily inactivated after blood collection in vitro. The inactivation is caused by the oxidation of sulfhydryl (SH), the active gene of the enzyme active center. Only through proper reduction can it be reactivated. Such as CK— NAC kit contains CK activator named N-acetylcysteine. The experimental study shows that it takes about 180 S for NAC to activate the inactivated CK in serum. This is the theoretical basis why CK determination should be delayed for a long time. When AST and ALT are determined by the method recommended by IFCC, pyridoxal phosphate needs to be pre-activated. It should be emphasized that biochemical reagents containing activators have higher results in determining enzyme activity.

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