Recombinant Protein General Handling Protocols
Recombinant proteins are essential tools in biochemical and immunological research, serving as both functional molecules and assay targets. Creative Biolabs provides quality-assured recombinant protein solutions and supports researchers with stepwise guidance to ensure experimental success.
Recombinant Protein Expression and Purification
Step 1. Choose Expression System
Select based on protein complexity and post-translational modification needs:
- E. coli: Rapid expression, cost-effective, limited PTMs
- Yeast (Pichia, S. cerevisiae): Moderate glycosylation capability
- Mammalian cells (HEK293, CHO): Ideal for complex eukaryotic proteins
- Baculovirus-Insect cells: Useful for high-yield and moderate PTMs
Step 2. Clone Target Gene
Insert the gene into the appropriate expression vector. Confirm correct reading frame, affinity tags (e.g., His, FLAG), and promoters.
Step 3. Express Recombinant Protein
Induce expression (e.g., IPTG for E. coli) and optimize time/temperature to minimize inclusion body formation.
Step 4. Purify Protein
Creative Biolabs recommends affinity purification as the first step.
- Nickel affinity purification or immobilized metal affinity chromatography: For His-tagged proteins
- Glutathione resin: For GST-tagged proteins
Additional purification via size exclusion or ion exchange chromatography may follow for higher purity.
Recombinant Blood Group Proteins Quantification Method
Creative Biolabs offers reliable quantification protocols to standardize recombinant blood group protein concentrations, ensuring batch-to-batch consistency for downstream assays such as ELISA or flow cytometry.
Step 1. Prepare Serial Dilutions
Generate a standard curve using BSA or another protein standard (0-1000 µg/mL). Run alongside your recombinant sample.
Step 2. Measure Concentration
- Preferred: BCA Assay (Creative Biolabs recommends for its detergent tolerance)
- Alternative: Bradford Assay (rapid, but less linear for glycoproteins)
Step 3. Validate Integrity
Use SDS-PAGE under reducing and non-reducing conditions. Western blot with tag-specific antibodies may confirm identity.
Reconstitution Buffer Choices
Creative Biolabs supplies most recombinant proteins lyophilized or frozen. Appropriate reconstitution maximizes stability and bioactivity while preserving functional integrity.
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For Carrier-Free Recombinant Proteins
- Reconstitute in sterile 1x PBS or a low-salt buffer (e.g., 10 mM Tris, pH 8.0) to reduce aggregation risk
- Add 0.1% BSA if protein is <0.1 mg/mL to prevent surface adsorption or loss due to binding to tube walls
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For Carrier-Containing Recombinant Proteins
- Use PBS + 0.1% carrier protein (e.g., BSA or HSA) to maintain protein solubility and stability during storage
- Avoid reducing agents or detergents unless validated for your application, as they may interfere with activity
Always perform gentle pipetting and mix by slow inversion—avoid vortexing, which may cause protein denaturation.
Storage Guidelines
Proper storage extends recombinant protein usability without compromising structural integrity.
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Short-Term (1-2 weeks)
- Store at 2-8°C in aliquots if used within two weeks
- Avoid repeated freeze-thaw cycles
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Long-Term
- Snap-freeze reconstituted protein in aliquots using liquid nitrogen
- Store at -80°C in sterile, low-protein-binding tubes
- Include cryoprotectants (e.g., 5% glycerol) if stability testing supports use
Creative Biolabs recommends validating activity post-thaw with functional assays where possible.
Creative Biolabs is committed to supporting your protein work at every step—from expression to storage. With decades of experience in recombinant protein production and handling, Creative Biolabs' technical team ensures reliability and reproducibility for a broad range of basic research applications. For assistance with custom expression systems, purification formats, or buffer selection, Creative Biolabs offers tailored consultation services. Let Creative Biolabs optimize your recombinant protein workflow today.
