1. E. coli Protein Expression System:

pET series vectors are currently the preferred choice for recombinant protein expression in E. coli. They have the lowest basal expression level, and target protein expression is regulated by inducer (IPTG) concentration. The T7 RNA polymerase mechanism is highly efficient and selective; upon full induction, almost all cellular resources are directed towards protein expression.

2. Yeast Protein Expression System:

Yeast Protein Expression System:

Common vectors for intracellular expression include pPIC3K and pPIC3.5K, while pPIC9K is commonly used for secretory expression. The selection marker for all is His4.

3. Insect Protein Expression System:

Common expression vectors include pFastBac1, pFastBacHT, and pFastBacDual. The commonly used expression cells are Sf9 cells.

4. Mammalian Protein Expression System:

Commonly used expression vectors include pcDNA3.1, pCEP4, pATX1, etc. Commonly used expression cells are HEK293 and CHO-K1 cells.

KMD Bioscience can provide recombinant protein expression services based on the four major expression systems. We can select different expression and purification strategies according to client needs to facilitate their research experiments.

KMD offers both native and recombinant protein purification services. The company provides affinity purification, size-exclusion chromatography, ion-exchange chromatography, and hydrophobic interaction chromatography.

1. Affinity-Tagged Protein Purification: For proteins containing affinity tags, affinity chromatography is typically the first step. Subsequent purification steps are chosen based on the obtained protein purity, properties, and the location of impurities.

2. Inclusion Body Protein Purification: For proteins expressed in inclusion bodies, purification is generally performed prior to refolding. The refolding buffer is screened through multiple rounds until the optimal buffer is selected. Common refolding methods include: (1) Dialysis and Diafiltration; (2) Gradient Refolding; (3) Matrix-Assisted Methods: HIC, SEC, etc.; (4) Molecular Chaperones; (5) Small Molecule Additives.

Simultaneously, KMD Bioscience has established a comprehensive large-scale protein fermentation and purification platform, capable of providing clients with industrial-scale fermentation technical services to meet their needs for large-scale protein expression and preparation.

KMD Bioscience's customized high-speed automated filling line can accommodate 0.1-10ml vials. Combined with our large-scale lyophilization equipment, we can provide clients with one-time protein aliquoting and lyophilization services for 100,000 vials (3ml each). The lyophilization process is complex and variable, influenced by numerous factors. With years of experience in protein research, KMD Bioscience is well-versed in lyophilization principles and operations. We can provide a complete solution based on client research needs. We can assist in selecting appropriate lyophilization conditions, optimizing and establishing the lyophilization process, particularly for lyophilized formulation studies. Based on our complete production process line, we can also deliver the final finished product directly to the client.

--We offer diversified services including plasmid construction, gene expression analysis, and recombinant protein expression to meet your diverse experimental needs.

--We have constructed pCold series vectors containing cold-inducible expression elements and engineered pET vectors to obtain dual-expression plasmids, safeguarding our clients' protein expression requirements.

--We formulate complete construction, expression, and purification plans within a short time based on client sample characteristics. We possess rich experience in recombinant protein preparation: having successfully prepared thousands of recombinant proteins for clients, including recombinant antibodies, secreted proteins, transmembrane proteins, proteases, etc., with a high success rate.

--We possess fermentation equipment of various scales: from 10L to 500L fermenters, meeting client needs for different fermentation volumes and expression systems in both research and production.

--We have high-quality industrial-grade lyophilizers capable of providing protein lyophilization services for 100,000 vials (3ml each).

--With a well-established protein platform, strict quality control systems, and skilled experimental personnel, we can provide downstream services related to proteins.

--Project Tracking: A regular reporting mechanism ensures you can remotely monitor experimental progress, with full project transparency.