Tryptones, Casein Peptones and Casamino Acids
Hydrolysates of milk casein. Tryptone is the standard nitrogen source in LB, TSB and other molecular biology and general-purpose media; casamino acids are the free amino acids from acid hydrolysis, used where a defined composition is needed.
Tryptone is casein digested with trypsin: rich in peptides and high in tryptophan, it is the core nitrogen source of LB Broth, Tryptic Soy Broth and other everyday media, and its tryptophan content makes it suitable for the indole test. Casein peptone is the general term for casein hydrolysed with different enzymes; degree of hydrolysis and peptide profile vary by product.
Casamino acids are the acid hydrolysate of casein, in which the protein is almost completely broken down to free amino acids (tryptophan is destroyed by acid hydrolysis). They suit formulations that need amino acids without many peptides, such as M9 and other semi-defined media, hybridoma work and certain vaccine processes. Polypeptone is a blend of casein and animal tissue hydrolysates with broader nutrition, often used for fastidious organisms and toxin production.
This page lists the tryptones, casein peptones, casamino acids and polypeptones supplied by STBIO MEDIA. Casein is derived from milk and is a milk allergen; Halal-certified versions are available for some products.
How to choose
- E. coli culture, plasmid preparation, recombinant protein expression: tryptone, consistent with the LB formulation.
- Formulations that need a defined composition with controlled peptides: casamino acids.
- Fastidious organisms, toxin or enzyme production: polypeptone or casein and meat blends.
- Cell culture: look for tryptone grades labelled clear solution and low endotoxin, and confirm with the specification sheet.
- To avoid milk allergen: look at soy or plant peptones instead.
Products in this group
29Casein peptones
Casein hydrolysed with other enzymes; the peptide profile varies by product
HalalREF. 19501HCasein Meat Peptone E2500 g5 kg25 kg- REF. 19501Casein Meat Peptone E2500 g5 kg25 kg
- HalalREF. 21520HCasein Meat Peptone FE1500 g5 kg25 kg
- HalalREF. 21189HCasein Peptone 103500 g5 kg25 kg
- HalalREF. 21181HCasein Peptone 103F500 g5 kg25 kg
- HalalREF. 21559HCasein Peptone BE50500 g5 kg25 kg
- HalalREF. 19546HCasein Peptone E1500 g5 kg25 kg
- HalalREF. 21266HCasein Peptone E195500 g5 kg25 kg
REF. 21328HCasein Peptone EGF1500 g5 kg25 kg- REF. 19544Casein Peptone Plus500 g5 kg25 kg
- HalalREF. 21362HCasein Peptone S150500 g5 kg25 kg
- HalalREF. 21330HCasein Peptone SP1500 g5 kg25 kg
Polypeptones
Mixed peptones blended from several protein sources
HalalREF. 21424HHipolypeptone-S500 g5 kg25 kg- REF. 21010HPolypeptone YF250500 g5 kg25 kg
- HalalREF. 21164HPolypeptone #J1500 g5 kg25 kg
- REF. 19222Polypeptone CMS-P23500 g5 kg25 kg
- REF. 19223Polypeptone MS-2110500 g5 kg25 kg
- HalalREF. 21009HPolypeptone SL250500 g5 kg25 kg
- HalalREF. 21008HPolypeptone YL250500 g5 kg25 kg
- REF. 19212Polypeptone YMS-1012110500 g5 kg25 kg
- HalalREF. 21071HPolypeptone YS-800E500 g5 kg25 kg
- HalalREF. 21069HPolypeptone YS-803500 g5 kg25 kg
- HalalREF. 19214HPolypeptone YSS-1013110500 g5 kg25 kg
Tryptones
Casein digested with trypsin; the standard nitrogen source for LB, TSB and the indole test
Casamino acids
Acid-hydrolysed, almost entirely free amino acids, for semi-defined media
Frequently asked questions
01What is the difference between tryptone and peptone?
Peptone is the general term for protein hydrolysates; tryptone is one specific kind, made from casein with trypsin. When a formulation specifies tryptone, do not substitute another peptone directly, as tryptophan content and peptide profile differ.
02Can casamino acids replace tryptone?
Usually not. Casamino acids contain almost no peptides and no tryptophan, and many strains grow more slowly on them than on tryptone. They are meant for formulations that need a defined amino acid composition, not as a general nitrogen source.
03Is there a Halal-certified tryptone?
Yes. Products whose code ends in H are Halal-certified; the product page shows the badge and certificate information.
Further reading
- LB Broth Recipe and Preparation: Miller, Lennox and Luria Formulations per LitreThe three standard LB (Luria-Bertani) formulations with grams per litre, how much agar for LB Agar, step-by-step preparation and sterilisation, when to add antibiotics, and the usual causes of failure.
- What Are Casamino Acids? Casamino Acids vs Tryptone vs Casein PeptoneCasamino acids are casein hydrolysed completely with hydrochloric acid, consisting almost entirely of free amino acids. How they differ from tryptone and enzymatic casein peptone in hydrolysis, tryptophan, salt and use.
- LB Broth Miller vs Lennox vs Miller #4: How to Choose the Right LB Liquid Culture Medium FormulationAll three formulations share the same ingredients and differ by a single number, but that number decides whether your experiment succeeds.