Protein service Protein Service

IMMUNOSTEP offers a wide range of services for the production and processing of recombinant proteins, from different protein expression platforms to a number of other protein services, such as the design of assays based on enzymes and antibodies, and customised processing and fabrication, for a great variety of applications and research areas. IMMUNOSTEP aims to be a reliable business associate by supporting research in and development of our clients' products.


Protein Expression and Purification

From a gene sequence, glycerol or plasmid, IMMUNOSTEP carries out its recombinant protein production project. Moreover, it offers a recombinant protein characterisation service:

  • Expression in mammalian cells.

    Transient transfection. Optimised expression and detection (293T, CHO and HEK cells). Post-translational modifications. Excellent method for the production of bioactive proteins.

  • Bacterial expression.

    Optimised expression and detection (E.coli). Rapid expression and easily scalable.

  • Expression in insect cells.

    Transient transfection and Baculovirus Expression Vector System (BEVS). Optimised expression and detection (Sf9 and Sf21 cells). Production and titration of recombinant baculovirus.  Post-translational modifications similar to the mammalian system. Suitable for the expression of toxic genes.

Different techniques used for the purification of recombinant proteins:

Ion exchange chromatography, affinity and molecular exclusion chromatography, or gel filtration chromatography.

  • Tags used: 6xHis, GST, FLAG.
  • Tag removal by means of proteases: Thrombin, PreScission, Factor Xa.


 FPLC AtkaExpress

Fig. 1: FPLC AtkaExpress – IMMUNOSTEP facilities.




Protein Characterisation

  • Electrophoresis in polyacrylamide gels with SDS and Coomassie staining.
  • Determination of protein concentration
  • Western blot
  • Absorption spectrum
  • HPLC
  • Mass spectrometry
  • Size exclusion chromatography


Lyophilisation Services

With the goal of increasing the stability and useful life of proteins, and reducing freight charges, IMMUNOSTEP offers customised protein lyophilisation services.

IMMUNOSTEP's great experience minimises the risks of loss of activity or protein aggregation that may occur during lyophilisation by selecting the excipients and stabilisers for the process and adjusting the conditions of the lyophilisation.


Stable Cell Line Development Service for the Production of Antibodies and Recombinant Proteins

IMMUNOSTEP offers the option of stable cell line development from cDNA or by using gene synthesis, thereby providing the customer with the stable clones which can produce overexpression of practically any protein of interest in the cell line selected.


Flow chart diagram of the transfection and development of a stable cell line:

Flow chart diagram of the transfection and development of a stable cell line

A complete report on the generation of the stable cell line and the best three clones will be provided.

How can we help you?

Thanks to our team of experts as well as the integration of the entire process in IMMUNOSTEP's facilities, the service department at IMMUNOSTEP has completed more than 100 projects involving the production of recombinant proteins for their use in functional assays, as antigens in the development of antibodies, structural analysis, and many other applications related to the production and characterisation of biomarkers and proteins of interest in areas such as diagnosis and therapy. Below are some examples of finished projects:


Service Description

Bacterial expression and purification.


Expression of the enzyme D-xylose-dehydrogenasein E.coli (BL21), purification by molecular exclusion chromatography and characterisation of the enzymatic activity.



Expression and purification in mammalian cells.


Transfection of CHO and HEK293 cell lines, expression and purification of membrane protein CD19 by affinity with a 6xHis tag. Analysis using WB.



Development of a stable cell line.


Construction of the target vector, transfection of cell line HEK293, validation of the expression of membrane protein CD34, using cytometry.