Biomaterial Database

Improved microbiological assay for penicillin residues in milk and dairy products. 1978

S E Katz, and C A Fassbender

The microbiological assay for penicillin residues in milk was improved. Acidification of milk with phosphoric acid to pH 4.5, centrifugation to remove precipitated proteinaceous matter, adjustment of pH to 6.0, a second centrifugation, and the use of a 2% agar base layer resulted in the consistent measurement of 0.01 unit penicillin activity/ml milk. Sarcina lutea was used as the assay organism. Recoveries in milk averaged 94%, in nonfat dry milk 84%, in cottage cheese 97%, and in cream cheese 94%.

UI	MeSH Term	Description	Entries
D008892	Milk	The off-white liquid secreted by the mammary glands of humans and other mammals. It contains proteins, sugar, lipids, vitamins, and minerals.	Cow Milk,Cow's Milk,Milk, Cow,Milk, Cow's
D010406	Penicillins	A group of antibiotics that contain 6-aminopenicillanic acid with a side chain attached to the 6-amino group. The penicillin nucleus is the chief structural requirement for biological activity. The side-chain structure determines many of the antibacterial and pharmacological characteristics. (Goodman and Gilman's The Pharmacological Basis of Therapeutics, 8th ed, p1065)	Antibiotics, Penicillin,Penicillin,Penicillin Antibiotics
D002417	Cattle	Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.	Beef Cow,Bos grunniens,Bos indicus,Bos indicus Cattle,Bos taurus,Cow,Cow, Domestic,Dairy Cow,Holstein Cow,Indicine Cattle,Taurine Cattle,Taurus Cattle,Yak,Zebu,Beef Cows,Bos indicus Cattles,Cattle, Bos indicus,Cattle, Indicine,Cattle, Taurine,Cattle, Taurus,Cattles, Bos indicus,Cattles, Indicine,Cattles, Taurine,Cattles, Taurus,Cow, Beef,Cow, Dairy,Cow, Holstein,Cows,Dairy Cows,Domestic Cow,Domestic Cows,Indicine Cattles,Taurine Cattles,Taurus Cattles,Yaks,Zebus
D002611	Cheese	A nutritious food consisting primarily of the curd or the semisolid substance formed when milk coagulates.	Cheeses
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001681	Biological Assay	A method of measuring the effects of a biologically active substance using an intermediate in vivo or in vitro tissue or cell model under controlled conditions. It includes virulence studies in animal fetuses in utero, mouse convulsion bioassay of insulin, quantitation of tumor-initiator systems in mouse skin, calculation of potentiating effects of a hormonal factor in an isolated strip of contracting stomach muscle, etc.	Bioassay,Assay, Biological,Assays, Biological,Biologic Assay,Biologic Assays,Assay, Biologic,Assays, Biologic,Bioassays,Biological Assays
D012505	Sarcina	A genus of gram-positive, anaerobic bacteria whose organisms divide in three perpendicular planes and occur in packets of eight or more cells. It has been isolated from soil, grains, and clinical specimens.