I5281 SAFC


PharmaGrade, Ajinomoto, EP, JP, USP, Manufactured under appropriate GMP controls for pharma or biopharmaceutical production, suitable for cell culture

Synonym: (2S,3S)-2-Amino-3-methylpentanoic acid

  • CAS Number 73-32-5

  • Linear Formula C2H5CH(CH3)CH(NH2)CO2H

  • Molecular Weight 131.17

  •  Beilstein/REAXYS Number 1721792

  •  EC Number 200-798-2

  •  MDL number MFCD00064222

  •  eCl@ss 32160406

  •  PubChem Substance ID 57654304

  •  NACRES NA.26



Related Categories Amino Acids, Analytical/Chromatography, Biochemicals and Reagents, Pharmacopoeia, Pharmacopoeia A-Z,
biological source   non-animal source
grade   EP
product line   PharmaGrade
assay   ≥98.5%
form   crystalline powder
mfr. no.   Ajinomoto
application(s)   cell culture | mammalian: suitable
impurities   endotoxin, heavy metals, residual solvents, tested
mp   288 °C (dec.) (lit.)
solubility   1 M HCl: 50 mg/mL
Featured Industry   Pharmaceutical (small molecule)
foreign activity   cytotoxicity, tested


General description

PharmaGrade products are manufactured under appropriate controls for use as a raw material in pharma or biopharmaceutical production. For more information on the PharmaGrade Program, visit
To request the Enhanced Quality Product Documentation for this product, please contact Customer Support and select ‘Product Documentation’. Please note that access to the Enhanced Quality Product Documentation for this product requires a confidentiality disclosure agreement.


L-Isoleucine is an essential amino acid. It can be biosynthesized from threonine or through fermentation of carbohydrates. The amino acid L-isoleucine is an isomer of L-Leucine, differing in the position of the side chain. It is also considered to be a branched chain amino acid, along with L-Leucine and L-Valine, which are sources of fuel and/or transport during cell development. It is used as a cell culture media component in the commercial biomanufacture of therapeutic recombinant proteins and monoclonal antibodies.

Safety & Documentation

Safety Information

NONH for all modes of transport
WGK Germany 
Protocols & Articles

Related Content

Amino Acids Reference Charts

Amino acids are the compounds or building blocks that make up peptides and proteins. Each amino acid is structured from an amino group and a carboxyl group bound to a tetrahedral carbon. This carbon ...
Keywords: Building blocks, Gene expression, Mass spectrometry

Enhanced Quality Program [VIDEO]

The Enhanced Quality Program is a quality management system that is used to differentiate products based on the required level of transparency, control and documentation support determined by the nee...

One Quality Policy [VIDEO]

Sigma-Aldrich maintains one quality policy on a global level to provide consistency in vision, maintained across all manufacturing and distribution sites so that the company on the whole is adhering ...

Quality Management Systems [VIDEO]

See how we combine the use of various Quality Management Systems to manage manufacturing and supply chain for our products, as well as ensure data integrity for information provided to customers via ...

Risk Management [VIDEO]

Our Quality Policy means that we are able to provide certain information to end customers based on a product’s Enhanced Quality level, and that information is limited to what we are able to guarantee...

Peer-Reviewed Papers


Related Products

Technical Service:

Our team of scientists has experience in all areas of research including Life Science, Material Science, Chemical Synthesis, Chromatography, Analytical and many others.

Bulk Ordering & Pricing:

Need larger quantities for your development, manufacturing or research applications?