I. Insulin is divided into which kinds 1. Animal sources: Mammals: (cattle, sheep, pigs, etc.) The amino acid sequence and structure of insulin molecules are slightly different from those of humans, with pig insulin being the closest to human. It is gradually eliminated due to the possibility of causing allergic reactions. 2. Genetic recombinant human insulin: recombinant DNA of yeast or recombinant Chinese hamster ovary cells (CHO) expresses synthetic human insulin with high purity, whose structure is the same as that of insulin secreted by the human body itself. Representative: Menthol insulin, Dettol insulin 3. Insulin analogues: It is the use of DNA technology to generate new insulin analogues that are more suitable for human physiological needs by using genetic engineering technology for human insulin structure and composition. Representative: glycine insulin, lysergic insulin. Second, how to store insulin in the end Unopened insulin is stored at 2-8 ℃, refrigerator storage until the expiration date of the package; must not be placed below 0 ℃, which will make insulin lose activity; insulin refills that have been opened and used should not be put back into the refrigerator, can be stored at room temperature, because the needle on the refill is connected to the outside world, repeated hot and cold alternation, easily lead to air into the bottle, affecting the dose Accuracy, can cause blood glucose instability, but also may cause bacterial contamination. Opened insulin can be stored at room temperature for about 4 weeks. Avoid direct heat source or sunlight, avoid shock, and the car is not a good place to put insulin when traveling, because the temperature inside the car may rise above 60℃ during summer sunshine, and such temperature will reduce the potency of insulin. It is also best not to put insulin on an ice pack, and it is good to carry it with you when you do airplane. Therefore, it is good to keep the opened insulin at room temperature and away from light, not in the refrigerator.