Protein tags, as fusion partners used in recombinant DNA technologies, enable effective, single-step affinity purification for various proteins/peptides with different characteristics. Despite this important advantage, tags as exogenous amino acids may alter the protein structure and biological functions. Therefore, non-tagged (tag-free) proteins or peptides are more preferred to ensure safety and efficacy, especially in the biopharmaceutical field. A recombinant protein with a fusion tag has limited possibilities for obtaining authorization from medical/drug administration agencies.
Based on the microbial biologics R&D platform, Yaohai Bio-Pharma offers customized non-tagged (Tag-free) protein preparation services dedicated to meeting unique objectives for research, development, and manufacturing for clinical use.
Keywords: tag-free protein production, non-tagged protein purification, free tag-based protein preparation, tagless protein expression and purification, highly tag-free target protein
Application: human medicine research, animal medicine development, recombinant vaccine development, recombinant large molecule biologics production
Our Microbial R&D Platform
We are experienced in microbial strain engineering, fermentation, and product purification.
Bacteria: Escherichia coli (E. coli)
Yeast: Pichia pastoris (P. pastoris), Saccharomyces cerevisiae (S. cerevisiae), Hansenula polymorpha (H. polymorpha)
Customized Options
| Modality |
Recombinant Protein |
| Starting Materials |
Gene sequences, recombinant plasmid, or engineered strains |
| Deliverables |
Purify: ＞80%, ＞85%, ＞90% Quantity: 0.2~10 g (to be determined by the project) |
| Expression System and Formation |
E. coli periplasmic secretion, soluble and inclusion body expression;
Yeast intracellular or secretion expression
|
| Analysis methods |
Ultraviolet (UV), bicinchoninic acid assay (BCA), Bradford, or Lowry for Quantity
Sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) for purify testing
Optional: Western blot (WB）, enzyme-linked immunosorbent assay (ELISA), high performance liquid chromatography (HPLC) |
| Residual impurities |
Endotoxin (optional) |
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