Creative BioMart provides rapid immunoprecipitation mass spectrometry of endogenous proteins (RIME) service to identify chromatin associated proteins (including but not limited in proteins complexed with epigenetic modifiers). This technique can be utilized in parallel with chromatin immunoprecipitation sequencing (ChIP-Seq) to provide information about cistrome and interactome for a given protein.

What Is RIME?

RIME is a recently developed technique that uses immunoprecipitation of the target protein and mass spectrometry to detect endogenous interacting proteins in formaldehyde cross-linked cells. This approach studies protein complexes in a rapid and robust manner and is very suitable for identifying transcription cofactors and chromatin associated proteins.

First, formaldehyde is used as a cross-linking agent to stabilize the protein complex. The cross-linked complex is immunoprecipitated by using antibodies against the endogenous target protein, rigorously washed, and then digested into peptides. Subsequently, the target protein and dozens of interacting proteins can be identified using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The combination with mass spectrometry technology makes this approach sensitive and able to identify high affinity or transient interactions of complexes composed of low abundance proteins.

Figure 1. Schematic of the RIME procedure (Mohammed H.; et al. 2016)

Features of RIME

1. Allowing the enrichment of endogenous proteins in a rapid and cost-effective manner
2. Allowing for rigorous washes, minimizing non-specific background noise and improving sensitivity
3. Capturing low-affinity interactions that are typically lost during washing
4. Enriched with endogenous protein complexes, eliminating artifactual interactions or perturbations caused by over-expressed protein levels
5. Allowing a limited amount of starting material (as few as 1×10⁶ cells)
6. When combined with ChIP-Seq, the obtained protein data complements the DNA sequencing data

Our Advantages

1. Tolerance of multiple sample types: we currently accept a wide range of biological and clinical samples including cells and tissue samples. Sample sources include human, animals, plants and microorganisms.
2. One-stop service: customers only need to provide samples, and Creative BioMart completes full RIME experiment from cross-linking, lysate preparation, immunoprecipitation, protease digestion, LC-MS/MS analysis and computational data analysis. We also offer free project consultation.
3. High quality data & Professional data analysis: we stringently control each step in the workflow to ensure access to unsurpassed data quality. We will provide data analysis upon request. The final report you will receive includes detailed protocols, raw data, analytical data, graphs, and a summary of findings.

Workflow of RIME Service at Creative BioMart

Our RIME service includes but not limited in cross-linking, nuclear isolation and sonication, immunoprecipitation, purification of proteins and tryptic digestion, LC-MS/MS and data analysis. Similar to all immunoaffinity techniques, the success of this technique and the amount of antibodies required depend on the specificity and affinity of the antibodies utilized. As a subsidiary of Creative Biomart with more than 10 years of experience in antibody manufacturing, we have confidence in the antibodies we use can meet the research needs.

Figure 2. Workflow of RIME service at Creative BioMart

With an experienced technical team, Creative BioMart can provide high-quality RIME service, ensuring the objectives are met and accelerate your epigenetic research. contact us for more information about our RIME service.

Reference
1. Mohammed H.; et al. Rapid immunoprecipitation mass spectrometry of endogenous proteins (RIME) for analysis of chromatin complexes. Nature Protocols. 2016, 11(2): 316-326.