Transformation of Expression Plasmids

Recombinant antibodies (rAbs) represent the fastest growing class of therapeutic proteins and widely used in the research and diagnostics. The effective transformation of expression plasmids is one of the most important steps to obtain quality antibody. Creative Biolabs has been an experienced service provider in the field of antibody development. At present, we provide a full range of rAbs production services against any target or the special transformation of expression plasmids service, and we believe our featured services and products will facilitate your attractive project.

Introduction of Transformation of Expression Plasmids

Transformation of expression plasmids is the process that exogenous DNA is transferred into the host cell. Transformation usually involves in the uptake of DNA into bacterial, yeast or plant cells. Commonly, transformation methods include chemical transformation, electroporation or particle bombardment. For chemical transformation, host cell is primarily treated by divalent cations such as calcium chloride to make the bacterial cell wall more permeable, thus exogenous DNA can be taken up easily. Besides, heat shock is used to temporarily form pores in the cell membrane, allowing the transfer of the plasmids into the cell. For the electroporation method, a short electrical pulse can endow the bacterial cell temporarily permeable. For particle bombardment, it is mainly used for the transformation of plant cells. Exogenous DNA can be physically forced into the cell by gene gun by coated the DNA construct on the gold or tungsten particles.

Fig.1 Plasmid design for expression of therapeutic proteins.¹

Transformation of Expression Plasmids for Production of rAbs

Once gene cloning of antibody is completed, plasmids are taken up into competent cells by transformation. During the transformation to express antibody protein, a suitable and competent cell strain should be selected. The following factors must to consider:

Genotype: the list of genetic mutations in the strain that distinguish it from wild-type E. coli.

Transformation efficiency: measurement of the amount of supercoiled plasmid successfully transformed into a volume of cells; defined as colony forming units per microgram of DNA delivered (cfu/μg).

Application: applications include routine cloning, protein expression, library production, etc.

Steps of Transformation of Expression Plasmids

• Thaw all reagents completely on ice.
• Add plasmids to thawed competent cells.
• Gently mix by tapping tube of competent cells.
• Incubate reaction on ice for 30 minutes.
• Heat shock the competent cell mixture by incubation for 30 to 60 seconds in a 42°C water bath.
• Incubate tubes on ice for 2 minutes.
• Add 250 to 500 µL of SOC or LB media.
• Incubate at 37°C and shake at 250 rpm.
• Warm selection plates to 37°C.
• Spread 10, 50, and 100 µL of transformed cells on selection plates.
• Incubate plates at 30°C overnight.

What Can We Do For You?

Creative Biolabs is one of the best partners for scientists in the process of custom antibody production. We now offer a full set of transformation of expression plasmids to help you obtain high-quality antibody production clone that may endanger the success of your antibody development project. Our experienced experts are dedicated to antibody production with the greatest chance to succeed. In addition, based on the commitment of prompt communication and on-time reporting, our staff will ensure a high-efficiency service to meet the strict project timelines. If you are interested in our custom antibody production services including the transformation of expression plasmids service, please feel free to contact us for more information.

Work flow of rAb production includes:

• Gene Cloning
• Transformation of Expression Plasmids
• Small-scale Expression
• Large-scale Expression & Bacterial Disruption
• Purification of Fusion Proteins
• Protein Concentration & Concentration Determination
• Detection Assays