Antibody Labeling and Crosslinking Service

KMD Bioscience provides a wide range of high-quality antibody labeling services. Antibodies and proteins can be cross-linked with different reporter enzymes, such as horseradish peroxidase (HRP) and alkaline phosphatase (AP), using different chemical coupling methods to maximize retention of labeled antibodies or enzymes' activity. Enzyme-labeled antibodies or proteins can be used in ELISA, immunoblotting, in situ hybridization, cell and histochemical assays.

KMD Bioscience established a complete strategy and calculation scheme to ensure that the enzyme/protein coupling ratio is close to 1:1 to maximize the activity. Antibodies have their unique properties, and we will perform quality control tests on antibodies before the enzyme-conjugated labeling process begins. It usually takes 1-2 weeks to complete the marking process, and we can also perform antibody or protein labeling according to customers' requirements.


The Antibody Labeling Services:


--AP (alkaline phosphatase) Labeling Service

Alkaline phosphatase (AP) is a hydrolase commonly used for antibody labeling. It catalyzes the formation of a yellow substance on p-nitrophenol. The absorbance is read at a wavelength of 405 nM. Its catalytic efficiency is much lower than that of HRP, the advantage is that the catalytic kinetic reaction is stable and the formed substrate is linearly accumulated.

--HRP (horseradish peroxidase) Labeling Service

HRP-labeled antibodies can be widely used in ELISA, Westerns Blot and immunohistochemistry (IHC). In ELISA experiments, HRP-labeled antibodies are usually used to catalyze blue chemicals in the substrate, which has the advantage of high catalytic efficiency. Usually, the color reaction can be completed in 10-30 minutes (AP: 2-4 hours).


--β-galactosidase Labeling Service

Beta-galactosidase (β-galactosidase) is widely used in enzyme reporting systems in molecular biology. Beta-galactosidase-labeled antibodies are commonly used in photometric assays and electrochemical enzyme-multiplied assay techniques (EMATs).


--Biotin Labeling Service

Biotin is also one of the biomolecules commonly used for antibody and protein labeling. It can bind to tetrameric streptavidin with high affinity, including streptavidin and neutravidin, which is widely used in Western Blot, IHC and ELISA.


--Glucose Oxidase Labeling Service

Glucose oxidase (GOx) is derived from Aspergillus niger and has a monomer molecular weight of 80 kDa, which catalyzes glucose to form hydrogen peroxide . The disadvantage is that it is easy to form a dimeric form. Glucose oxidase-labeled conjugates are commonly used in sensor preparation for food industry fermentation process detection and diabetes diagnosis.


--Antibody Fluorescent Dye Marking Service

Unlike enzyme labels, fluorescent dyes are small molecule compounds. Our excellent scientists will follow the most stringent quality control regulations and perform dual monitoring of QC and QA for each marked item. The fluorescent dye including:


Fluorescein Derivatives Rhodamine Derivatives
Coumarin Derivatives BODIPY Derivatives
Cascade Blue Derivatives Lucifer Yellow Derivatives
Phycobiliprotein Derivatives Organometalic Compound
FAM series FITC


Main Process:


After the antibody-enzyme coupling process, the final conjugate needs to be removed, such as reducing agents, which can generally be removed directly by dialysis. However, in specific cases, additional purification techniques such as ultrafiltration, tangential flow (TFF) and gel chromatography are required for conjugate purification. If the cross-linking enzyme molecular weight is close to or greater than the antibody to be labeled, the molecular weight of the protein, affinity chromatography purification, ion exchange column and hydrophobic column chromatography are most commonly used.

Cross-linking conjugates ultimately require biochemical and biophysical analysis, such as MALDI-top, ESI, LC-MS Fluorescence, SDS-PAGE, IHC and enzyme kinetic analysis to ensure optimal quality production. Meanwhile, our QC (quality control) and QA (quality assurance) programs provide a double quality assurance for customers' products, allowing customers to control every aspect of the customized production. 


How to Order?

If you have any questions regarding our services or products, please feel free to contact us by E-mail: or Tel: +86-400-621-6806;