Improve MS-based biomarker determination with immunocapture

During the past decade, mass spectrometry, notably LC/MS, has become a major approach to identify and quantify proteins in patient samples. It includes analysis before treatments to find the proper biomarkers for cancers diagnostics, and monitoring of the arising of the anti-drug antibodies in human plasma after therapies. Despite the fact that MS has pretty high sensitivity and specificity, research in biotherapeutics requires even more. Immunocapture, and so specific protein enrichment, offer an interesting immunoassay solution. Here, we present simple to use and efficient reagents to improve the immunocapture and thus the output of the MS technology.

Get a reliable biotin conjugated antibody against the target protein

It’s challenging to get an antibody against the specific target. It’s even more difficult to make a reliable conjugation to biotin.

The solution has come this year, with the Chromalink kit. It is a comprehensive and easy to use kit that allows simple monitoring of the conjugation by Nanodrop UV-scan, without the need for HABA assays which are laborious, inaccurate, and consume large amounts of biotinylated sample. The conjugation is ensured by the HyNic (succinimidyl-6-hydrazino-nicotinamide) to 4FB (4-formylbenzamide) chemical reaction that generates also a UV-traceable linker.

Antibody conjugation

Antibody conjugation to biotin (protein) with simple UV-scan monitoring

3 kits depending on the quantity of antibody

Small magnetic beads with higher binding capacity to improve the pull-down

Reliable conjugation of biotin is not sufficient for immunocapture. The second major step is the capture itself of the immune complex (antigen-antibody) with streptavin beads. The choice of the beads matter a lot. We offer small (1µm diameter) and 12X higher binding capacity beads called Nanolink (>1700pmol/mg). The beads are produced based on the same innovative conjugation, the Chromalink technology.

Co-immunoprecipitation

Immunoprecipitation with Chromalink AB-biotin conjugation and Nanolink streptavidin magnetic beads Nanolink

Taking altogether, the biotin antibody conjugation kit and the Nanolink magnetic beads improve the development of an emerging kind of immunoassay based on immunocapture and mass spectrometry.

Dimitri Szymczak, PhD
Written by Dimitri Szymczak, PhD
Dimitri Szymczak is a Technical Support Specialist and Product Manager at tebu-bio, and a fan of capoeira in his spare time.