Recombinant Protein Expression in Insect Cells

Outside of E. coli and mammalian cells, insect cells, or baculovirus expression systems, are very common choices for recombinant protein production. This type of expression system possesses its own unique advantages, making the system suitable for a subset of target proteins. Similar to yeast cells, insect cells are capable of producing proteins with eukaryotic translational machinery. In addition, insect cells can be used to produce large proteins and intracellular proteins. Compared to other systems, insect cell expression involves a longer process, due to the requirement for an extra step of virus preparation. The whole process can take up to 16-20 weeks to complete.

General Workflow

1. Construction of Recombinant Donor Plasmid

2. Transformation into E. coli

3. Extraction of Recombinant Bacmid 
& Transfection into Insect Cells

6. Scale-up & Purification

Virus titer plaque assay

Target protein

5. Virus Titration & Expression

Recombinant virus particles

4. Virus Generation

Steps Breakdown

Steps

Timeline

1) Gene synthesis, codon optimization, and DNA prep

2 weeks

2) Bacmid preparation ,transfection and expression evaluation

2-3 weeks

3) Infection of insect cells and titration of the virus

1-2 weeks

4) Expression, evaluation, and optimization

2 weeks

5) Scale-up Production

Inquiry

6) Final QC and Delivery of Product

Case Studies

Optimized Baculovirus Expression

  • Strategy: 

    • P1 Virus generation (transfection of insect cell with recombinant Bacmid DNA)

    • Expression test of P1 stock, WB test

    • 200mL P2 virus generation

    • 3 column purification using gel filtration/Ni affinity and ion-exchange column chromatography

  • Deliverables: 

    • 1.3 mg protein

    • >90% purity

P1 Transfection and P2 Virus Generation Data

Chromatography and Final Sample QC Data