Preparation process of fluorescein-labeled chitosan:
In 100 ml with 1% chitosan 01 mol l acetic acid solution, add 100 ml of methanol, then slowly add 1 set volume of 20 mg ml FTIC methanol solution. After 3 h of reaction in the dark at room temperature, use 02mol l NaOH precipitates the labeled product. The pellet was centrifuged at 10 000 r min for 15 min and washed with a methanol aqueous solution at a volume ratio of 70:30. Wash and centrifuge several times until no fluorescence is detected in the supernatant (x = 485 rm, em = 535 nm). The labeled product is resoluble in 100 ml 0.1 mol l acetic acid, dialyzed in the dark for 3 days, freeze-dried.
In addition to chitosan, common polysaccharides also include hyaluronic acid, which is a class of biological polysaccharides with a large molecular weight. Using chemical and enzymatic methods, it was found that HA is composed of a repeating disaccharide composed of N-acetyl-D-glucosamine (GLCNAC) and glucuronic acid (GLCA). After the disaccharide is bound by 1 3, it is combined into a ha chain.
Fluorescein isothiocyanate (FITC) is a widely used low-molecular compound, with a maximum absorption wavelength of 490-495 nm and a maximum emission wavelength of 520-530 nm, showing distinct yellow-green fluorescence. It has the advantages of high quantum efficiency, long fluorescence lifetime, good photostability, and low temperature coefficient, and is widely used in hybridization probes, degraded protein sequences, and antibody labeling.
Related reagents: Cy7-NH2 cyanine dye Cy7 amino.
Cy5-Cooh cyanine dye C5 carboxyl group.
Cy5-NH2 cyanine dye Cy5 amino group.
cy5.5-NH2 cyanine dye Cy55 amino.
Cy3-NH2 cyanine dye Cy3 amino.
Chitosan