Recombinant Antibody (IgG) Production Services

Our recombinant antibody production services include: 1) Codon optimization and synthesis of antibody variable regions (VH and VL) or whole IgG antibodies for molecular construction of recombinant IgG antibodies with our proprietary antibody expression vectors; 2) transient production of recombinant antibodies in CHO cells; 3) multiple-step purification of recombinant antibodies; 4) quality control with SDS-PAGE, SEC-HPLC, and endotoxin measurement; if needed, mass spectrometry may be used to check molecular weight of the purified antibody. The recombinant antibody production services can be used to check not only the in vitro and in vivo activity but also the yield of the recombinant IgG antibodies.

Synthesizing antibody variable regions (VH and VL):
Including sequence optimization, for free, to meet goals such as recombinant antibody expression at high and reliable levels. 

Construction, expression, and purification of whole IgG antibodies (choice of human IgG1 or mouse IgG2a backbone; other recombinant IgG construction is available upon request):
* Fuse VH and VL into human or mouse IgG constant region backbone in antibody expression vectors;
* Transiently express the recombinant IgG antibody in CHO cells;
* Purify the recombinant IgG antibody with Protein A and if needed, at least one additional purification method.

Different antibody constant regions can be expressed with the same antibody variable region to produce chimeric antibodies, which is called isotype switching or class switching. For example, the IgM isotype can be switched to the IgG isotype. The switched chimeric antibody keeps the antigen affinity resulting from the same variable region but interacts with different effector molecules because of the different constant regions. The IgG backbone options include but are not limited to:
* Human IgG1, IgG2, IgG3, IgG4;
* Mouse IgG1, IgG2a, IgG2b, IgG2c, IgG3;
* Rat IgG1, IgG2a, IgG2b, IgG2c;
* Rabbit IgG;
* Canine IgG.

Deliverable:
A. Purified antibody from CHO transient production;
B. Study report.

Celetrix cell electroporation large-scale model SLT (11-0104) is a unique electroporation machine for large scale protein transient production in CHO cells: 8 ml to 400 ml. It is simple and useful for recombinant antibody transient production by CHO cells. Features of the CHO cell electroporation machine for transient production:

1. The largest scale (10 ml electroporation tube): 2x10^9 CHO cells per electroporation transfection for 400 ml CHO transient production; the smallest scale (0.2 ml electroporation tube): 4x10^7 CHO cells per electroporation transfection for 8 ml CHO transient production.
2. High efficiency/viability: only 10-20% CHO cells are dead after electroporation.
3. Preset program with single adjustable parameter; no need for custom programming.
4. For 200 ul, 1 ml, 5 ml, and 10 ml electroporation tubes.

Celetrix electroporation model SLT enables scalable transient protein production in CHO cells. The yields from 8 ml to 400 ml CHO transient production using 200 ul, 1 ml, 5 ml, and 10 ml electroporation are consistent because the principle is the same. The whole process is easy and convenient: CHO cells are spun down, resuspended with electroporation solution, and after 1-click and 2-second electroporation, transferred to CHO cell culturing media.

The yield of transient production in CHO cells using the cell electroporation model SLT is much higher than the other methods. The yield from transient gene expression (TGE) can easily reach 1 g/L for trastuzumab after 14-day cell culturing of the original 2x10^9 CHO cells in our hands.

Questions and Answers about the Recombinant Antibody Production Services:

Question: Why do you use at least 2-step protein purification methods to purify recombinant antibodies?
Answer: Protein A, G or L affinity chromatography is commonly used for antibody purification. However, for most antibodies, one-step purification is not enough to remove impurity, such as aggregate of the antibodies, endotoxin, and host cell protein or DNA residual. Impurity may interfere the in vivo and even in vitro activities of the purified antibodies. The impurity may vary lot to lot, and result from many factors such as DNA ratio of the heavy chain to the light chain during transfection of the host cells. I meant the DNA ratio in individual host cells. To minimize lot to lot difference, it is better to obtain high purity antibodies using multi-step purification methods. Many people thought that the quality of antibodies used for in vitro diagnostics (IVD) kits do not have to be high. However, sometimes the lot to lot difference is so significant that the kit performance is poor.

Question: Is the yield from 14-day fed-batch cell culturing double that from 7-day cell culturing?
Answer: Generally speaking, yes. If not, it does not make much sense to do 14-day fed-batch cell culturing. Even double is not enough. Generally, we expect 2-10 folds of antibodies in the 14-day fed-batch cell culturing compared with the 7-day cell culturing.

Question: Our antibody is a mouse IgG1. Are the prices the same as described above?
Answer: The cost of protein G purification is a little higher than protein A purification. The protein G resin is more expensive.

Question: We are doing high throughput screening (HTS) of a large number of recombinant antibodies. Protein A one-step purification is enough. Can you do 30 ml, 10 ml or even 4 ml transient production?
Answer: Sure, please contact us.

Question: Compared to 3 or 4-day transient production, what is the advantage of 7-day and 14-day cell culturing programs?
Answer: More antibodies are produced from 7-day and 14-day cell culturing programs. Also, one can know better about the potential yield of a recombinant antibody molecule from 7-day and 14-day cell culturing programs.

Related services:
Clone and sequence hybrimona antibody VH and VL
Construction, expression, and purification of single-chain antibodies (scFv-Fc) antibodies
Generation of stable cell lines expressing antibodies

Recombinant IgG Reference Antibodies:
Recombinant Human IgG1 Reference Antibody
Recombinant Human IgG2 Reference Antibody
Recombinant Human IgG4-S228P Reference Antibody
Recombinant Mouse IgG1 Reference Antibody
Recombinant Mouse IgG2a Reference Antibody
Recombinant Mouse IgG2b Reference Antibody

Fc ELISA Kits and Reagents:
Human Fc ELISA Kit
Mouse Fc ELISA Kit
Human Fc ELISA Reagent Kit
Mouse Fc ELISA Reagent Kit