Post Translational Modifications

Post translational modifications (PTMs) are biochemical alterations to one or more amino acids of a protein. PTMs, which occur after protein translation, can have profound effects on the protein's function, interactions, half-life, and subcellular location. Thus, PTMs expand the human proteome from ~20,000 nonmodified canonical proteins to an estimated 1 million – 1 billion different protein species1,2,3.

RayBio® PTM Assays

RayBio® products enable high throughput analyses of PTMs, including phosphorylation, glycosylation, methylation, acetylation, nitration, hydroxylation, proteolytic cleavage (e.g., caspases), and carbonylation.


Covalent addition of a phosphoryl group (-PO3-), most often to a serine, threonine, or tyrosine residue.


Covalent addition of a sugar molecule, often classified by the atom to which it binds (e.g., N-linked, O-linked).


Covalent addition of one to three methyl groups to an amino acid.


Covalent addition of an acetyl group to primary amino groups, hydroxyl groups, or sulfhydryl groups.


Covalent addition of a nitro group (-NO2) to tyrosine, tryptophan, cysteine, or methionine residues.


Covalent attachment of a hydroxyl group (-OH), which most often occurs on proline.

Proteolytic Cleavage

Formation of shorter protein chains by breaking peptide bonds.


Covalent adduction of lipid aldehydes to lysine, histidine, or cysteine.

Full Testing Services

Send us your samples, we’ll send you results! Contact us to learn more.

Featured PTM Research Products

Phosphorylation Pathway Profiling Array C55

Simultaneously detects 55 phosphorylated human proteins in the MAPK, AKT, JAK/STAT, NFκB, and TGFβ signaling pathways.

Receptor Tyrosine Kinase (RTK) Phosphorylation Array

Simultaneously detects 71 phosphorylated human receptor tyrosine kinase proteins.

Human Glycosylation Array 1000

Simultaneously detects the glycosylation profile of 1,000 human proteins.

RayBiotech also offers ELISA kits to measure transcription factor activity. Fast, easy, high throughput, and sensitive! Learn more here.

Can't find what you’re looking for? We'd love to hear from you! We continually expand our offerings based on customer feedback. Please contact [email protected].


  1. Kelleher, N.L. A Cell-Based Approach to the Human Proteome Project. J. Am. Soc. Mass Spectrom. 23, 1617–1624 (2012) doi:10.1007/s13361-012-0469-9
  2. Ponomarenko EA, Poverennaya EV, Ilgisonis EV, et al. The Size of the Human Proteome: The Width and Depth. Int J Anal Chem. 2016 May 19; 2016: 7436849. doi: 10.1155/2016/7436849
  3. Aebersold R, Agar JN, Amster IJ, et al. How many human proteoforms are there? Nat Chem Biol. 2018 Feb 14; 14(3): 206-214. doi: 10.1038/nchembio.2576