Library Display-Based VHH Discovery

The capacity of constructed library can be evaluated by the number of colonies present on the transformed plates with serial repeated dilutions. Calculate the average of all dilution plates after counting colonies, which indicates the library size (cfu/mL).

The quality of constructed library can be determined through QC colony PCR. Some colonies are randomly picked from the titration plates and used for colony PCR to analyze the insertion of the correct size.

The diversity of constructed library can be determined through QC sequencing. Some colonies are randomly picked from the titration plates and used for sequencing and alignment to evaluate the diversity. It is well known that most of the diversity of the antibody molecule is found in the complementarity-determining regions (CDRs).

Immune library is the best-fit choice for specific project purposes, such as some specific target antigens, the high-affinity antibody requirement from nanomoles to picomoles, the largest possible number of antibody clones, improved probability to obtain the exact immune response.

Creative Biolabs can provide several excellent premade libraries which have great diversity to be able to derive specific antibodies. They can be used for rapid discovery of high-potency sdAb against any targets and allow to save your time and cost from library construction.

In essence, the naïve library is constructed by the cDNA isolated from non-immune animals. The RNA from several animals can be mixed to generate one qualified naïve library.

Creative Biolabs can accept properly stored tissues and RNA as starting materials for library construction. Please note, at least 50 μg total RNA or 10 μg mRNA is required for one library construction project.

After the screening process, Creative Biolabs can offer two general strategies to identify target-specific binders and then perform corresponding functional assays to select desired sdAb candidates.

Strategy 1: Monoclonal Phage-based Binder Identification & Validation
To isolate specific binders against the target of interest, a group of monoclonal phage clones is randomly picked and gone through a series of validation processes to obtain the sequence of identified positive clones. We can also generate the purified sdAbs for further characterization assays, such as affinity measurement.

Strategy 2: Magic™ Therapeutic Antibody Discovery Platform-based Binder Identification & Validation
Creative Biolabs has established the Magic™ Therapeutic Antibody Discovery Platform which is an exclusive high-throughput solution for the identification of all potential novel binders at one-time. Purified sdAbs can be generated from the sequence of identified clones for further characterization assays, such as affinity measurement.

In general, we need around 6-9 months to complete an immunization-based novel sdAb discovery project, thereinto, the immunization process will spend about 3 months to achieve acceptable immune responses. By screening our premade libraries, only 3-4 months is required to identify new sdAb binders.

Yes. Generally, we can provide small aliquots of outputs (phages) after library screening as well as supernatants of validated positive clone (phage-free), which may vary due to different project design. Please note, these materials are not included in the default deliverable list because the stability cannot be 100% guaranteed (especially for oversea delivery). Please notify us at the early stage if you want to receive these materials, they may be charged accordingly.

The helper phage provided by Creative Biolabs does not contain lacZα but carries the kanamycin-resistant gene for antibiotic selection, thus cannot be distinguished through blue-white screening.

The pfu, refers to the plaque-forming unit, is a measure of the quantity of individual infectious particles, and is usually used to count bacteriophage.

The cfu, refers to the colony-forming unit, is a measure of viable cells in which a colony represents an aggregate of cells derived from a single progenitor cell, and is usually used to count bacteria (e.g. E. coli).

Yes. Recombinant anti-M13 Major Coat Protein Antibody (CBMAB-0206MC) or other custom anti-M13 antibodies are available of your choice. Please inquire us for more details.

1. Project report including the library construction & screening processes.
2. Constructed library (do not apply to premade library screening).
3. Sequence information of the final identified positive binder(s).