Antibody Production & Characterization

Twist supplies clonal gene glycerol stocks from the clonal genes synthesized for antibody production. During antibody production, the DNA is consumed for transfection; however, glycerol stocks are reserved and delivered along with the antibodies post-production. Please see our protocol for preparing fresh DNA from glycerol stocks.

A leader or secretory signal sequence acts as a peptide signal bound by cellular machinery early in the translation process. This allows for the correct localization of the translation complex to the endoplasmic reticulum where the antibody chains can enter into the secretory pathway for protein assembly and secretion from the cell. The leader sequence is cleaved during the protein assembly process and is not a part of the final protein. Twist recommends the following leader sequence for both heavy and light chains when using our pTwist IgG expression vectors as these sequences have been tested and validated with our pTwist vectors in both Expi293™ and ExpiCHO™ cell lines:

VH: MRAWIFFLLCLAGRALA

VL: MRAWIFFLLCLAGRALA

The Kozak sequence directs the pre-initiation complex (PIC) and ribosome to the translation initiation site (start codon) and mediates ribosome assembly ensuring the correct protein sequence is translated.

The consensus Kozak sequence is generally considered as GCCGCCACCATGG, where ATG is the start codon (typically the start of the signal sequence). Twist recommends the version GCCGCCACC upstream of the start codon ATG.

You can use a Protein A or G solid phase to purify, which binds to the FC region of the antibodies, depending on species and isotype of IgG. Alternatively, you can use immobilized antigen (full length or short peptide antigen) to purify the antibodies. The method will depend on the downstream application and specificity of the antibody.

Twist uses the industry standard cell lines, Thermo Fisher Scientific Expi293™ and Thermo Fisher Scientific ExpiCHO™

Customers may select the pTwist CMV BG WPRE Neo expression vector when they would like to use their own Fc region sequence (IgG3, Mouse IgG, or modified Fc) or have another type of Fc-fusion antibody to express.

Please remember to include a stop codon at the end of your coding sequence. If you have any design questions, please email igg@twistbioscience.com for help with your custom request.

Research has shown that C-terminal lysine residues of the heavy chain (present on all IgG isotypes) are cleaved off once the IgG is in circulation. Studies have also shown that there is no functional impact of the lysine once it's cleaved and its presence is actually inhibitory to allowing the antibody to reach full cytotoxicity potential: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4622059/

This cystein in a full IgG forms a disulfide bond with the LC constant region which is not present in the VHH-Fc fusion construct.

Please ensure you have the following sequence format for uploading variable regions:

• Removed signal leader peptide (if using pTwist vectors + Twist recommended signal leader peptide)
• Variable regions should not end with any CH1 starting sequence
• Sequences are divisible by three if your ORF is in line with your insertion site

You can find the pricing table for our custom antibody products in your account by clicking here.

If you need to contact your Account Manager regarding pricing, their contact information is available in eCommerce under Account.

Antibodies are typically supplied in standard commercial Phosphate-Buffered Saline (PBS). Depending on your application parameters, you can specify alternative pH preparations—such as PBS at pH 7.4 or custom configurations like PBS at pH 6.0—directly through the portal configuration window.

Final metrics vary based on individual antibody sequence expression characteristics. Standard yields break down across the following parameters:

• 1 mL Scale: Delivers a final elution volume of approximately 220 µL, with target yields ranging from 15 µg to 300 µg.
• 8 mL Scale: Delivers a final elution volume of approximately 750 µL, with target yields ranging from 15 µg to 3,000 µg.

To ensure seamless compatibility with downstream laboratory automation systems, microfluidics arrays, and fluid handlers, products can be specified in several array configurations:

• 96-deep well plates featuring fully customizable grid array mapping.
• 1.4 mL matrix-compatible micronic tube racks.
• Individual specialized tubes available in 2 mL, 4 mL, or 10 mL capacities (10 mL tubes are optimized for large volume supernatant shipments).