PTM-Specific Antibody Preparation Service

Many proteins carry post-translational modifications — phosphorylation, methylation, acetylation, glycosylation, ubiquitination and others — and the presence or absence of a modification at a specific site often determines what the protein does. Detecting a modification requires an antibody that recognizes the modified form while ignoring the far more abundant unmodified protein. That specificity is the entire challenge of a post-translational modification (PTM) antibody project.

Two levels of specificity are possible. A pan-modification antibody reports the overall level of a modification across a proteome or a lysate, while a site-specific antibody distinguishes a modification at one particular residue of one protein. Site-specific reagents demand far more careful antigen design and screening, and some modification types are harder to target than others: phosphorylation antibodies are the most established, acetylation and methylation become progressively more difficult, and glycosylation varies strongly with the size and position of the attached glycan.

We design and prepare PTM-specific antibodies using careful antigen design and negative screening to suppress recognition of the unmodified protein, with the level of specificity agreed at the start of the project so the reagent matches the question.

What the Service Covers

• Pan-modification antibodies – reagents that report the overall level of a given modification in a sample, useful for comparing lysates or tissues.
• Site-specific modification antibodies – reagents that recognize a modification at a defined residue, for example a specific phosphorylation, methylation, or acetylation site.
• Antigen design and negative screening – immunogens built around the modified and unmodified forms, with screening that excludes candidates reacting with the unmodified protein.
• Glycan-aware design – adjustment of the approach for glycosylation targets, where the size and position of the glycan change what can be recognized.

Choosing the Level of Specificity

Modification Types and Their Difficulty

Workflow

• Define the target and specificity level – agree the modification, the site, and whether pan-modification or site-specific recognition is required.
• Design the antigen – construct immunogens that present the modified and unmodified forms appropriately.
• Generate candidates – produce a panel of antibodies by the appropriate route.
• Screen with negative controls – select candidates that recognize the modified form and do not react with the unmodified protein.
• Deliver – supply the antibody with the screening data that support its specificity.

Applications

• Signaling research – detecting the phosphorylation state of a protein across conditions.
• Epigenetics and chromatin studies – recognizing specific histone methylation and acetylation marks.
• Formal modification surveys – comparing overall modification levels between samples with pan-modification reagents.
• Functional studies – linking a specific modification site to a change in protein behavior.

Why Work With Us

A PTM antibody is only useful if it can tell the modified protein from the unmodified one, so we treat specificity as the specification and screen against it. We choose the antigen design and the specificity level that fit the question, use negative screening to remove cross-reactive candidates, and are straightforward about where a particular modification is intrinsically difficult, so the project scope matches reality rather than expectation.