Custom Monoclonal Antibody Discovery Services

Custom recombinant rabbit monoclonal antibodies for difficult targets and application-specific performance

The antibody you need is not always ready-made. Custom antibody programs can be challenging when target biology is complex, the optimal epitope is unclear or inaccessible, or screening does not yield antibodies suited to the intended application.

Our technical team works with you to create a development plan with clear timelines and project milestones. In-house antigen design capabilities support the project from the beginning, while the development approach is adapted around your assay and performance requirements.

Build recombinant rabbit monoclonal antibody candidates around your target biology, epitope requirements, and assay goals. From antigen design through clone selection and scale-up, you receive a milestone-based program with multiple candidates to evaluate and a path to reliable ongoing supply.

Discuss Your Target

Match Your Antigen Design to Your Discovery Goal

Selecting the right antigen design strategy early can help reduce project risk, limit rework, and improve downstream success. Through our collaboration with Precision BioTools, we offer EPISOLVE™ and EPIVOLVE® targeted epitope design options alongside sequence-defined antigen design.

These options provide flexibility to align the development approach with your target biology and discovery goal.

Antigen Design Options	Supports	De-risking Benefit
EPISOLVE™ / EPIVOLVE® targeted epitope design	Functional specificity, including PTM recognition, and reduced cross-reactivity	Increases the likelihood of obtaining fit-for-purpose antibodies from the start
Sequence-defined antigen design	Early discovery and candidate diversity	Avoids early commitment to the wrong epitope and preserves discovery flexibility

How the process works

Starting with your protein target, we design an immunization strategy using in-house generated antigens, so the project is aligned to your needs from the beginning.

You then evaluate multiple candidate clones, allowing final selection to be based on measured performance rather than assumptions. From antigen design to clone selection, our approach is built to reduce uncertainty and support antibody programs that perform as intended.

What you gain

Better control over antigen design and QC
Multiple candidate clones instead of a single black-box result.
Greater confidence that the final antibody will work in your application
A development path shaped around your needs, not a generic workflow

Project at a Glance

A milestone-based development plan keeps your antibody project transparent, collaborative, and aligned to your application from the start.

Milestone 1

Discovery & Candidate Generation

Client consultation
Antigen design & production
Immunization
Single B-cell isolation & screening

~3 months

Milestone 2

Recombinant Expression & Testing

Clone selection
Recombinant expression
Client-led fit-for-purpose testing

<2 months

Milestone 3

Scale-up & Supply

Scale-up selected clones (mg > g)
Easy reordering
Ongoing supply support

<2 months

Start A Project

Workflow

Client Consultation

Antigen Design & Production

Immunization

Single B-cell Isolation & Screening

Clone & Express
Recombinant mAbs (ug)

Fit-For-Purpose
Testing by Client

Scale-up of Selected
Clones (mg)

On-going Supply
(mg > g)

Capabilities and Target Types

We develop custom monoclonal antibodies across a range of target classes, including membrane proteins, secreted proteins, intracellular proteins, post-translational modifications, anti-idiotype targets, and small molecules.

Our monoclonal antibody generation platform delivers diverse clone sets to support customer-driven fit-for-purpose selection. We develop antibodies with your downstream application needs in mind, including assay performance and matched antibody pair requirements.

Cell surface, secreted, and intracellular targetsBuilt for common protein classes across discovery, research, and assay development.
Post-translational modifications (phospho-specific antibodies)Useful when you need modification-specific recognition with strong assay performance.
Anti-idiotype antibodiesDesigned for programs requiring specificity against antibody variable regions.
Small moleculesSuitable for low-molecular-weight targets that require specialized immunogen and screening strategies.

Western blot
Immunohistochemistry
Immunofluorescence
Immunoprecipitation
ELISA
Flow cytometry
Epitope binning for matched antibody pairs

Monoclonal antibody reformatting
Binding pair selection by competition binning
Validated antibody manufacturing

Customer Case Studies

“We’ve been consistently pleased by Fortis’s initial candidate success rate. We’re now engaged in multiple projects with Fortis, with several anti-PTM clones about to be launched as formal genomic mapping reagents.”

Michael-Christopher Keogh, PhD

Chief Scientific Officer
EpiCypher Inc.

Read Case Study

“Some companies only splenectomize and proceed with one rabbit, whereas Fortis immunizes multiple rabbits, and these are all screened for antibodies to provide a distribution of the best potential candidates. In this way, we receive multiple options for performing our own screens.”