Prokaryotic (E. coli) Expression Service

Alpha Lifetech Inc. focuses on recombinant protein expression in different Biosystems for many years, including prokaryotic and eukaryotic organisms, as well as the development of novel high-potency recombinant proteins to meet customers' requirements.

E. coli expression system, one of the prokaryotic systems of protein expression, is a famous and convenient protein expression system, known for its competitive price and high productivity for producing proteins. The basic procedures included in the process of protein expression are as follows:


Custom Service & Procedures:


Phase: Procedures



I. Gene Analysis and Synthesis

2 weeks


-- Codon Optimization

-- Amplification/Isolation of target gene

-- Subcloned target gene into bacterial expression vector

-- Verification of the authenticity of the subcloned gene by restriction enzyme digest and sequencing.


II. Transfection & Expression

1 week


-- Transfection of recombinant constructs into high-efficiency expression bacterial strain.

-- Expression optimization: induction time, temperature and IPTG concentration and so on.

-- SDS-PAGE, Coomassie blue staining and Western blot with tag-specific or custom-supplied antibody.

-- Silver staining (option)


III. Up-Scale Culture

2 days


-- 1L of bacterial culture will be induced with inducer and harvested for protein purification.


IV. Purification

1 week


-- Affinity purification: Ni-NTA (for 6 x HIS-tagged proteins); glutathione (for GST-tagged proteins) column

-- Non-affinity purification: IEX

-- Native or denatured condition


V. Endotoxin Control & Tag-free

4 days


VI. QC Control

3 days


-- SDS-PAGE, Western Blot or MS report



5 weeks



Service Features:


-- High Success Rate: more than 95%

-- Fusion-Tag Selection: Single Tag or Combined Tags

-- Supernatant Protein Expression: Matrix Screening (over 48 conditional Permutation and combination)

-- Fermentation Advantage: Various Scales (1, 5, 10, 30, 80 L fermenter)

-- Time & Products: Short Time Cycle; High purity (no less than 95%)