Protein services

Customized and high quality proteins and conjugates

The combination of our profound expertise in protein expression and conjugation with consumer knowlegde from our Laboratory Services unit enables us to give optimal advice to our clients. To find the best solution for your application we select between tailor-made solutions or standard procedures. Recombinant proteins, antibodies and conjugates are developed according to customer specifications and can be produced up to preparative scale.

Our Dialog

In dialog with the customer we exploit for each task the optimal technical solution.

Microcoat’s protein services includes

Microcoat provides high-quality and cost-effective contract fermentation and downstream services for recombinant protein production. Microcoat owns modern fermentation and downstream-processing equipment that is operated by skilled and experienced professionals. Bench scale and pilot scale fermenters up to 30 L are available for fermentation development, optimization and production.

The fermentation material is further processed and purified following either transferred protocols or specifically adapted purification protocols (after a development and optimization phase).

Our primary expression hosts is E. coli. Fermentation protocols for different strains are established. For expression of more challenging proteins eukaryotic expression systems are available.

Protein expression

Cloning of target gene into chosen expression vector
Initial protein expression analysis in small scale
Scale-up of fermentation or cell culture
Scale-up of recovery and purification process
Creation of fusion or tagged proteins, if desired
Expression optimization specific to host organism
Development of protein recovery and purification strategy
Optimization of protein recovery and purification strategy


Cultivation of

E. coli and eukaryotic expression systems

Strain development and optimization
Process development and optimization
Pilot-scale production

Downstream processing

Chromatography purification (IEX, affinity, HIC, SEC)
Endotoxin removal
Inclusion body preparations
Protein refolding
Product harvest and concentration by ultrafiltration
Freeze drying
Quantification and purity assessment (UV/VIS, SDS-PAGE, Western Blot, HPLC)

Antibodies represent the most essential component in nearly all immunoassays. Their quality strongly influences the performance of the assays and lot-to-lot variances can lead to readjustment or even revalidation of a developed test.

To be able to control the quality of a final diagnostic product at all points of the production process, Microcoat preferably purifies and modifies antibodies in house. But we also share our experience to make the best out of your antibody as a stand-alone service.

Antibody purification

For polyclonal or monoclonal antibody purification from serum and culture supernatant we rely on a set of well-established and proven standard procedures to optimize yield, purity, and immunoreactivity of your antibody.

For challenging specifications regarding purity and cross-reactivity specific resins for affinity chromatography or immunoadsorption can be custom-made. For quantification, purity assessment and functional testing different analytical methods are available (UV/VIS, HPLC, SDS-PAGE, Western Blot, ELISA, Biacore®).

size exclusion chromotography (SEC)
Affinity chromatography (protein A, protein G, positive or negative immunoadsorption)
Ion exchange chromatography (IEX)

Antibody production

Within the framework of a custom development project, Microcoat also cares about the coordination of all steps of an antibody production project.

Animal immunization and phage display screening are conducted in collaboration with experienced and certified contract partners.

Cloning, recombinant antigen expression and purification of antigens
Polyhapten synthesis
Custom monoclonal antibody production (classic or via phage display)
Custom polyclonal antibody production

Antibody modification

Fab cleavage
F(ab‘)2 cleavage
Blocking of functional groups
Crosslinking for immunization

Enzymatic or chemical antibody modification can be required to reduce undesired non-specific effects or to improve sensitivity.

Depending on your requirements, you can choose between cost-effective standard conjugation procedures or you rely on our profound expertise in assay development, conjugation and protein chemistry to develop the optimal conjugation strategy. Dependent on the later application, a number of variables need to be considered like the type of conjugate, degree of labeling or protection of potential epitopes. Standard conjugation protocols are often not suitable for proteins sensitive to aggregation and buffer exchange or for dilute protein solutions.

Our customers stay in close contact with our conjugation specialists during planning and realization phase. We can accommodate virtually any scale, from small scale R&D to full prep scale.

Labeling of antibodies or antigens with e.g.

Biotin (via different functional groups / direct or with linker / chromogenic)
Fluorescent dyes (with low-molecular dyes or proteins like phytoerythrin)
Special labels: Europium, Ruthenium
Customer-specific haptens

Preparation of protein – protein conjugates e.g. antibodies with

Horse radish peroxidase
Alkaline phosphatase

Particle Conjugates: Protein, Peptides, Small Molecules

Colloidal gold
Colored or uncolored latex (different sizes)
Fluorescent latex
Magnetic particles

Streptavidin gold (40 nm), streptavidin latex (blue, 500 nm) and streptavidin magnetic particles can be ordered from stock. They only have to be conjugated with biotinylated antibodies, antigens or binding proteins. This step can be performed either in our labs or at the customer’s side.

We prepare conjugates for any application, including

ELISA development and manufacture
Lateral flow assay development and manufacture
As a partner in funded projects

Colloidal gold

Colloidal gold is a suspension of gold nanoparticles with intensely red color. It is used as a sensitive direct label for rapid diagnostic tests (test strips). For this application the gold particles must be conjugated to the specific protein component.

Two different methods are established

Direct conjugation of proteins to colloidal gold
Binding of biotinylated proteins to universal streptavidin gold

Streptavidin gold

Microcoat’s proprietary procedure provides gold conjugates with excellent stability and lot-to-lot reproducibility.

This is achieved by using the modular streptavidin-biotin system

Colloidal gold is conjugated to streptavidin. This conjugate is very stable and can easily combined with any specific component.
The specific component (e.g. antibody) is mono-biotinylated according to an established procedure in order to avoid aggregation.
Combination of streptavidin gold with the mono-biotinylated protein yields stable gold conjugates.


Streptavidin gold is available from stock.
Streptavidin gold - specification sheet

Benefit from our one-stop solution:

Assay development and validation

We develop highly specific and robust assays based on your indivual reagents

Assay development and validation

We develop highly specific and robust assays based on your indivual reagents

Bioanalytical services

using your assay for the routine measurement of samples coming from your non-clinical and clinical studies

Bioanalytical services

using your assay for the routine measurement of samples coming from your non-clinical and clinical studies

Kit manufacturing

Production of final kits according to your specification

Kit manufacturing

Production of final kits according to your specification