1. Congo red dye and pectin can combine with water to form a red colloidal solid. Red colloidal solid is pectinase produced by the reaction of pectin and Congo red, and red is the color of pectinase. Pectinase is an enzyme that decomposes pectin, the main component of plants.
2. Congo red can be used for double dyeing with Soviet Union and starch-like dyeing. Because it can be dissolved in water and alcohol, it should be cleaned and dehydrated quickly.