How do you isolate and purify insulin?

Insulin can be isolated and purified from pancreatic tissue, typically from pigs or cattle, through a series of extraction and chromatography steps. First, pancreatic tissue is homogenized and subjected to acid or alcohol extraction to release insulin. Then, the solution undergoes techniques like ion-exchange chromatography and affinity chromatography to separate insulin based on its charge and binding properties. Finally, further purification steps such as recrystallization or high-performance liquid chromatography (HPLC) ensure the insulin is of high purity for therapeutic use.