Primary conjugated antibodies from St John's Laboratory

Why choose directly conjugated primary antibodies

Directly conjugated primary antibodies possess a reporter label (fluorophore, enzyme, or tag) bound directly to the antibody molecule. This approach simplifies workflows and enhances signal detection.

Key benefits of direct conjugation

• Streamlined protocols – direct conjugated antibody protocols have fewer incubation and wash steps compared to indirect methods
• Reduced background noise – no cross-reactivity from secondary antibodies
• Monoclonal and polyclonal options available
• Faster protocols and results – ideal for high-throughput experiments or limited sample availability
• Improved reproducibility – direct labeling ensures consistency across experiments
• Targeted multiplexing – multiple antibodies, each conjugated to a unique label, can be used simultaneously

Why choose primary conjugated antibodies for multiplexing?

Multiplexing allows for the simultaneous detection of multiple targets in a single sample. Compared to using a combination of primary and secondary antibodies, directly conjugated primary antibodies offer a streamlined and efficient alternative that is perfectly adapted for multiplexing purposes.

Our primary conjugated antibodies make multiplexing simple and effective:

• Unique spectral separation: Each antibody is linked to a specific fluorophore, enabling easy distinction between targets. This separation is essential for accurate parallel analysis in microscopy, flow cytometry, and other imaging techniques.


• Preserve precious samples: Analysing multiple markers from a single tissue section or cell preparation, enables you to extract maximum information from your limited samples, ultimately saving time and resources.


• Reduced workflow complexity: Eliminate the need for matching a primary with a species-specific secondary. Using directly conjugated primary antibodies simplifies workflows, significantly reducing the risk of non-specific binding, which can lead to false positives.


• Scalable design: Confidently design a simple dual-label experiment or a complex large multicolor panel. Our primary conjugated antibodies offer a scalable design that adapts to your research needs while being both affordable and budget-friendly.

Conjugated primary antibody options for every application

Immune system & cell surface markers

Our comprehensive immune system antibody portfolio encompasses an extensive array of reagents targeting T cells, B cells, natural killer (NK) cells, and myeloid subsets. This portfolio features multiple clones specific for critical surface markers such as CD8, CD19, and CD20, alongside NK cell markers, including CD56. Additionally, we provide a broad spectrum of T cell receptor (TCR) subunit antibodies, which enable researchers to conduct in-depth analyses of immune repertoires with unparalleled accuracy.

Our checkpoint inhibitor antibody portfolio—including PD-1, PD-L1, PD-L2, TIGIT, ICOS, BTLA, and members of the TIM and B7 families, as well as VISTA—serves to facilitate impactful research in immunotherapy and translational oncology. Each antibody is offered in a variety of conjugates such as PerCP, PE, APC, and FITC, ensuring seamless integration and compatibility with flow cytometry applications and multiplex analysis.

This extensive selection of antibodies provides an essential foundation for comprehensive immune profiling, allowing the dissection and characterization of immune responses with precision and reliability.

Cytokine & cytokine receptor pathways

Cytokine biology is crucial for understanding inflammation, autoimmune diseases, and cancer research. Our comprehensive antibody collection includes members of the IL-17 family, the IL-10 axis, as well as IL-21, IL-22, IL-23, and IL-31. We also offer essential receptor partners, including IL21R, IL17RA, and IL13RA2. This diverse panel allows scientists to explore the signaling pathways that drive immune activation, chronic inflammation, and tissue repair.

Additionally, our primary conjugated antibodies targeting growth factors FGF21, BMP9, GAS6, and SHH, along with their receptors, support research in developmental biology and metabolism. Map cytokine networks in real time using our wide range of fluorochrome-conjugated antibodies.

Cancer-associated antigens & glyco-markers

Cancer research requires tools that can accurately identify tumor-associated antigens with high specificity and wide coverage. Our portfolio provides exactly that, featuring classic mucins such as MUC1, MUC4, MUC16/CA125, and MUC17, as well as glyco-epitopes like Tn, STn, TF-Ag, Lewis Y, and sLea (CA19-9). These targets are not only established biomarkers but also serve as active immunotherapy targets for vaccine and CAR-T programs.

Additionally, we offer tumour markers, such as PSCA, Mesothelin, CA9, CSPG4, GPA33, DLL3, and B7-H3, which are essential for both solid tumor and liquid biopsy research.

Cell adhesion, extracellular matrix, and receptor signalling: advancing cancer research

Cell adhesion molecules and receptor tyrosine kinases play pivotal roles in cancer metastasis, immune cell trafficking, and key developmental pathways. Our extensive antibody portfolio includes critical components, such as cadherins (CDH17, CDH19), integrin ligands, and adhesion molecules (e.g., ALCAM, NECTIN-2, NECTIN-4), as well as a range of Wnt pathway receptors (FZD1, FZD4, FZD10, pan-FZD, LGR4).

Antibodies targeting essential signalling targets, including EGFR, ERBB4, DDR1, ALK, and MST1R, provide robust tools to study oncogenic signalling pathways and the mechanisms underlying therapeutic resistance. Our offerings are particularly adapted to research focused on cell signalling, models of metastasis and receptor-targeted therapeutic strategies.

Additionally, our broad range of conjugates enables seamless integration of these markers into functional assays and high-dimensional flow cytometry panels, thus enhancing experimental workflows and increasing overall efficiency in research applications.

Antibodies for infectious disease, autoimmune disease and neuroscience research

Our extensive portfolio of directly conjugated antibodies detect key proteins related to infectious diseases, autoimmune disorders and neuroscience research. We provide validated reagents for pathogen studies including Mycobacterium tuberculosis and Staphylococcus aureus, supporting health research on antimicrobial resistance and vaccine development. Complement pathway tools (C3AR1, C5b-9 complex) and immunoglobulin-specific antibodies (IgM, IgE) are critical for autoimmune and allergy studies, while neurological markers such as MOG, SLITRK6, and LINGO1 support neuroinflammation and demyelination research.

Why choose conjugated primary antibodies from St John's Laboratory?

• Rigorously validated for specificity and sensitivity.
• Available across human, mouse, rat, and other species
• Offered in a range of clones, isotypes, and conjugate formats
• Supported by validation data to guarantee accuracy and reliability

Need assistance choosing your antibody reagents. We are happy to help! Contact us for more information!