What methods have been tried in the purification of penicillin?

The purity of penicillin was very low at first. If you want to extract a drug that can treat malignant patients, you need to fill a train car with culture solution. Later, they cultivated mold with corn juice, and the content of penicillin increased tenfold; Using excellent strains isolated from many parts of the world, the output of penicillin has increased from two units per cubic centimeter (one unit is 0.625 micrograms) to 40 units at once. To their great excitement, Penicillium found on a rotten watermelon made the output of penicillin soar from 40 units per cubic centimeter to 200 units.