Bac to Bac System

Creative BioMart has more than 10 years of experience in protein expression and is competent to satisfy various protein expression desire. We are expert in protein expression (intracellular or secretory), signal peptide selection, insect cell selection and culture. Choosing our Bac-to-Bac comprehensive service, customers only need to provide the coding sequence of your target protein. We will provide customized services from codon optimization to large-scale expression and purification.

Components of Bac-to-Bac System

Bac-to-Bac is one of the best developed insect baculovirus expression system. The classic Bac to Bac system mainly relies on Tn7 site-specific transposition between donor plasmid and Bacmid to generate recombinant baculovirus. Its ability to efficiently prepare recombinant baculovirus and producing high concentration post-translational modified protein makes it perfectly suitable for heterologous protein expression. The Bac-to-Bac expression system is generally consisting of:

Donor plasmid which carries the interest fragment between two Tn7 transposition site
Bacmid which contains Tn7 target site
E. coli DH10 which hosts Bacmid and contains a helper plasmid

Figure 1. Components of Bac-to-Bac System

Service Details of Bac-to-Bac System

Here is the service process, which is very flexible. Customers can choose to start from or stop at any step they want. For more technical information or enquiry, please feel free to contact us.

Step		Service Description	Timeline	Deliverables
1	System Selection （Optional）	Select donor vector (pFastBacTM 1/HT/Dual) Select host insect cell line (Sf9, Sf21, High Five)	——	——
2	Gene Synthesis & Subclone Construction	Sequence design and codon optimization Gene synthesis Subclone the interest sequence to the donor plasmid	1-2weeks	Enzymatic / Sequencing validation report.
3	Recombinant Baculovirus Production	Preparation of recombinant Bacmid Transfect the insect cells with recombinant Bacmid Produce P1 Virus stock (low titer), P2 Virus stock (high titer), P1, P2 Western Blot and titer assay	2 weeks	Recombinant virus suspension WB report Titer test report
4	Small-Scale Expression & Purification	P2 virus transfect insect cell Protein purification SDS-PAGE, Western Blot	1.5 weeks	Target protein sample Quantitative test report
5	Optional Services	System optimization Secondary purification Tag removal Activity assay	1-2 weeks	Optimization solution Protein product Protein activity report
6	Large-Scale Expression & Purification (1-10L)	Culture amplification Western Blot Purification	1-3 weeks	Purified Protein QC report

Donor Vector and Insect Cell Line

In order to optimize the expression approach, donor vectors and insect with unique advantage are available at Creative BioMart.

Donor Vector

Donor Vector	Advantage	Use
pFastBac 1	Offers strong polyhedrin promoter for high level, native protein expression Large multiple cloning site for simplified cloning	Suitable for high-level protein expression
pFastBac HT	Offers strong polyhedrin promoter Has an N-terminal 6xHis tag for sample purification Has a TEV protease cleavage site for tag removal	Suitable for secreted protein
pFastBac Dual	Contains two strong promoters Able to conduct simultaneous expression of two protein in insect cell	Suitable for simultaneous expression of two protein in insect cell

Insect Cell Line

Insect Cell	Advantage	Use
Sf9 (Spodoptera frugiperda)	Well-characterized host cell, good for plaquing	All general types of recombinant baculovirus production and protein expression
Sf21 (Spodoptera frugiperda)	High yield of intracellular protein	Intracellular recombinant baculovirus production and protein expression
High Five (Trichoplusia ni)	High yield of secreted protein, shorter culture period	Secreted protein expression

Choose Creative BioMart Bac-to-Bac Protein Expression Service

Choose Creative BioMart Bac-to-Bac protein expression service, we provide

Diverse systems

Diverse donor vectors and insect cell lines are available here, as well as scientific and reasonable expression solution design.

High success rate

Expression success rate is over 95% at Creative BioMart. Our mature technology platform promises to save your money and time.

Shorten expression period

It takes only 7 weeks on average from gene synthesis to large-scale expression

Completive service

Just provide the sequence of the target protein and we will solve the rest of problem for you.

Please note that all products/services provided are for research use only. Not intended for any clinical use.