title: Penicillin titer after storage of Penicillium chrysogenum by liquid nitrogen refrigeration.
mesh_terms: D001681:Biological Assay; D046508:Culture Techniques; D005615:Freezing / Q000009:adverse effects*; D009584:Nitrogen; D010406:Penicillins / Q000032:analysis* / Q000494:pharmacology; D010407:Penicillium / Q000378:metabolism*; D012505:Sarcina / Q000187:drug effects; D013045:Species Specificity; D013210:Staphylococcus / Q000187:drug effects; D014021:Tissue Preservation
chemical_list: D010406:Penicillins; D009584:Nitrogen