G&P Biosciences offers a complete suite of custom solutions for your antibody R&D. We can develop hybridomamonoclonal antibodies against your antigen of interest. We can clone and sequence the variable regions for your hybridoma antibodies. We can express and purify recombinant antibodies & derivatives to assess their binding to your target antigen. We can humanize your non-human antibodies using in-house algorithm & antibody expression technologies. We can conduct antibody epitope mapping, affinity maturation and additional services tailored to your needs. We also provide one-stop shop bundled services, starting from antigen preparation, hybridoma isolation, affinity determination, antibody humanization and engineering to custom-scale (up to gram quantities) production. 

Custom Hybridoma Monoclonal Antibody

(Service Code: AS-001)

We provide custom mouse hybridoma development for producing monoclonal antibodies against your antigen of interest. We guarantee at least two independent hybridoma clones with positive ELISA or Western blot results for any protein antigen (at least 2 mg with >80% purity provided by the client or custom-made by G&P Biosciences – please see our “custom protein production service” for more information). Our hybridoma team will work closely with you on every aspect of the process, including antigen preparation, immunization strategies, and primary & secondary screening assays, which are essential for a successful hybridoma campaign. 

Multiple hosts or stains will be employed in immunization using our optimized adjuvant and dosing strategies to produce the most diverse antibody repertoire possible. Using the techniques developed in-house, our custom hybridoma antibody services consistently deliver high success rate with proven abilities to generate hybridomas against difficult targets (e.g., multi-pass transmembrane proteins). Upon request, we can also screen your hybridomas using multiple assays (e.g., cell-based ELISA, flow cytometry) to identify specific clones according to your specifications.

Custom Hybridoma Antibody Sequencing

(Service Code: AS-002)

We will determine both heavy and light chain variable regions (VH and VL genes) from the hybridoma clones you provide. The mRNA samples will be prepared from your hybridoma cell pellets.  The VH and VL genes, including the leader sequences, will be isolated from the mRNA samples using our PCR-based 5’-RACE with a panel of specific primers. The PCR products will be subcloned into a cloning vector and typically at least 10 independent colonies will be sequenced for each of VH and VL genes. Upon request, we can also clone the full-length heavy and light chain genes for your determination of the isotype/subclass and generation of constructs to express recombinant mouse or chimeric IgGs to confirm their antigen-binding properties (see “Custom Recombinant Antibody Production” below for more information).  Using our standardized cloning and sequencing protocol, we are able to deliver the VH and VL sequence results to you with almost 100% success rate and fast turnaround time.

Custom Recombinant Antibody Production

(Service Code: AS-003)

We offer custom recombinant antibody (primarily IgG and derivative) production in mammalian cells (HEK293 or CHO).  Simply provide us with your VH and VL genes’ nucleotide or amino acid sequences and indicate the species, isotype, subclass and format (full-length or fragment) to be delivered. We will design, synthesize and assembly your VH and VL genes with proper constant regions or antibody fragments before subcloning them into our unique mammalian expression vectors. The constructs are usually codon optimized and contain signal leaders allowing maximum expression and secretion in mammalian cells. Alternatively you can provide us with the VH and VL genes that have already been cloned into a mammalian expression vector of your choice. 

We can design and produce your recombinant antibody or fragment originated from many different species(e.g., human, mouse and rabbit), isotypes (e.g., IgG, IgM, IgA & IgE), and subclasses (see the IgG structure and feature list below) as wells as many fragment-based derivatives, such as Fab, F(ab)’2, minibody,scFv and bispecific (scFv)2.  In addition to these options, we can engineer you antibodies with mutant constant regions, e.g., those with modified effector function or with mutant residue(s) for site-specific conjugation.  We can modify them to include additional tag or fusion, e.g., immunostimulatory cytokines and protein markers such as GFP, luciferase, HRP for easy detection and quantification.

We can start by sequencing the V genes from the hybridoma clone you provide and then construct them into our unique expression vectors. We can generate chimeric constructs (e.g., mouse-human chimeric IgG) for your antibody humanization project.  With our expression systems, we can generate stable antibody expressing cell lines in just 2 weeks. We will then perform 50-100 ml pilot production to evaluate the feasibility and productivity. It allows us to deliver 0.1to 1 mg of recombinant antibody for your initial testing in just 3 weeks. We can further expand for large-scale production in the range of milligram to gram quantities.  We normally purify antibodies with protein A and other chromatography depending on your requirements.  Our customrecombinant antibodies usually exceed 95% purity and can be formulated into any buffer compatible with your downstream assays.

Custom Antibody Humanization

(Service Code: AS-004)

We offer custom antibody humanization services using in-house algorithm for rational design in combination with our cutting-edge high-throughput gene cloning & expression technologies.  We can create a humanized antibody that is essentially identical to a human variant with only the non-human origin of its complementarity determining region (CDR) segments responsible for binding to its target antigen (see the data example below for more information). We have 100% success rate in design & humanization of over a dozen of of non-human antibodies from clients and in-house products. 

Our humanization process includes the creation of a mouse-human chimera (mouse V genes fused to human constant regions) in an initial step to confirm its desired binding properties. Thereafter the chimera is further humanized by grafting CDRs into a human antibody “scaffold” and by selective alteration of specific amino acids in the frameworks if necessary. Typically 2-4 humanized VH and VL variants will be designed and constructed for expression in mammalian cells.  All antibody variants will be purified and assessed for their binding affinity to the target antigen. At least 1 humanized antibody variant showing an affinity of within 3-fold of that of chimeric antibody will be delivered. Upon request, we can perform affinity maturation of the humanized antibody to create variant(s) with greater affinity.

Bundled Service Package

One-Stop Shop Solution: Gene-To-Antibody

(Service Code: AS-G2A)

We offer bundled custom antibody production & engineering services, “Gene-to-Antibody”, a one-stop shop solution with standardized workflow and turnaround time. Bundle discount is included when you order target antigen preparation, hybridoma antibody screening, and recombinant antibody production & engineering from G&P Biosciences at the same time. Our one-stop shop services can start from any of the following steps: (1) antigen expression and purification; (2) immunization & hybridom isolation; (3) antigen-antibody binding assay development; (4) hybridoma V gene sequencing; (5) chimeric & humanized recombinant antibody production; (6) antibody affinity determination & characterization. In addition you have the options with different species, formats, fusions or tags for your final product (see the IgG structure and feature list above).

To request this bundled service, simply provide us the DNA nucleotide or protein amino acid sequence for your target antigen of interest, and indicate the type and format of antibody to be delivered. Upon receipt of your request, our service team will contact you with detailed experimental plan, design, milestone, timeline, and pricing information. Our goal is to be a partner you can trust and depend on for your antibody R&D.  We are determined to deliver high-quality antibody that recognizes your target antigen with high specificity and high affinity tailored to your needs in a timely manner.

We have a collection of pre-made, high-quality, recombinant antibodies against an array of target antigens, such as cytokines, growth factors, surface receptors and enzymes. They can be searched to retrieve the antibodies against your protein of interest by key word, protein/gene synonym, family, classification, disease association, and biological pathway (click here to search and retrieve your antibody). If you cannot find an antibody product against your protein of interest in our catalog or need a different format or variant, we can produce it as a custom service project. To discuss your needs and request more information, please contact us by email: This email address is being protected from spambots. You need JavaScript enabled to view it.

Data Example

A custom antibody sequencing, humanization & production project is shown below as examples to demonstrate the excellence & efficiency of our one-stop shop solution, “Gene-to-Antibody” services:

Example #1:

Hybridoma V Gene Cloning & Sequencing

The client requested custom design and generation of a humanized antibody from a mouse hybridoma monoclonal antibody raised against a target antigen X. We first extracted mRNA from the hybridoma cell pellet and isolated the VH and VL genes (including the leader sequences) by PCR-based RACE with a set of mouse VH and VL primers, respectively.  The PCR products were analyzed and purified by gel electrophoresis (see the image below). One pair of mouse VH primers (H3) and two pairs of VL primers(L3 & L4) specifically amplified ~450-bp DNA products by PCR, consistent with the estimated sizes for the mouse VH and VL genes.

All above three PCR products were subsequently inserted into a cloning vector.  DNA samples were prepared from ten independent colonies for the VH-H3 PCR product and five independent colonies for each of VL-L3 & VL-L4 PCR products. DNA sequencing analysis (data not shown) revealed that all ten VH-H3 clones encoded an identical protein amino acid sequence highly homologous to mouse VH gene products.  Moreover all ten VL clones yielded an identical protein sequence closely related to mouse VL gene products. Using in-house optimized protocols, we were able to deliver the V gene sequence results to the client and initiate the antibody humanization process in just 10 days.

Example #2:

Antibody Humanization Design & FWR Sequence Comparison

We next constructed the chimeric and humanized antibodies using above V gene sequences from the hybridoma clone provided by the client. We designed a pair of humanized VH and VL by grafting the mouse light chain and heavy chain CDR segments into a human IgG1,k “scaffold”. Sequence alignments showed that all mouse VL and VH framework regions (FWR1-3) display an average of 60-70% sequence identity to those derived from the human antibody “scaffold” (see the table below). In contrast, all three FWRs from the humanized VL we designed are 100% identical to those from the human “scaffold”. For the humanized VH, both FWR1 & FWR2 are 100% identical to those from the human “scaffold” and FWR3 is ~90% identical with an overall identity of 96%. Thus the humanized antibody we designed is almost identical (~98% for all FWRs) to a natural human antibody variant, containing only minimal non-human origins of CDRs responsible for antigen-binding.  We next expressed both chimeric and humanized antibodies in CHO cells and purified them to further characterize their antigen-binding properties. 

Example #3:

Recombinant Chimeric & Humanized Antibody Production

The chimeric & humanized V genes were assembled with a consensus Kozaksequence followed by the signal peptide sequence, mouse or humanized variable region, and human light chain or heavy chain constant region. The codon-optimized sequences were synthesized and inserted into our mammalian expression vectors. The heavy chain and light chain constructs were transfected into CHO cells to produce stable cell lines expressing chimeric or humanized antibody. The chimeric and humanized antibodieswere further purified from the cell conditional media using protein A affinity chromatography.  SDS-PAGE analysis indicated that both purified recombinant antibodies are >95% pure under non-reducing and reducing condition (see the gel image below). 

Example #4:

Antibody-Antigen Binding Affinity Determination by ELISA

The antigen-binding affinity constant (Kd) for the chimeric or humanized antibody was determined by ELISA (see the data plot and curve fit below). Following the incubation with serially diluted chimeric or humanized antibodies, the bound antibodies were detected by HRP-conjugated goat anti-human IgG Fc-specific secondary antibody. The binding curves were plotted and further fitted using one-site specific binding non-linear equation to calculate the apparent binding affinity constant (Kd) value for each antibody. From three independent measurements, the humanized antibody consistently showed a higher affinity binding to the target antigen with an average Kd of ~4 nMthan that of the chimeric antibody (Kdof ~10 nM). The humanized antibody showed 2-3 fold increase in the antigen-binding affinity comparing to the chimeric antibody, indicating that our humanization algorithm & strategy successfully preserve the original CDR conformation for antigen-binding. The humanized antibody was delivered to the client for subsequent cell-based and in vivo efficacy evaluation.

At G&P Biosciences, we are determined to provide you the best services for your antibody R&D. With decades of experience in antibody production and engineering, we excel on every aspect of the process (antigen preparation, hybridoma campaign, antibody humanization & engineering, antibody expression & purification). We want to be a partner you can count on to produce and engineer your antibody. In addition to the custom solutions described above, we also offer custom antibody binning, epitope mapping, affinity maturation and other antibody engineering services for your specific needs. 

If you have any question or need more information, please contact us by email: This email address is being protected from spambots. You need JavaScript enabled to view it.