Unconjugated antibodies and antibody fragments

Flexible unconjugated secondary antibodies for custom labelling and sensitive immunodetection

Unlike conjugated secondary antibodies, unconjugated antibodies are not directly labelled with reporter molecules such as fluorophores, enzymes, or biotin, allowing researchers to select and optimise the most suitable detection chemistry for their specific workflow. Therefore, unconjugated secondary antibodies and antibody fragments provide researchers with maximum flexibility for assay development, signal amplification, and custom labelling strategies across a wide range of immunodetection applications.

Typically raised against species-specific immunoglobulins of the primary antibody, unconjugated secondary antibodies are widely used in western blotting, immunohistochemistry (IHC), immunofluorescence (IF), ELISA, flow cytometry, and microscopy applications, particularly high resolution, and super-resolution imaging, where sensitivity, flexibility, and multiplex capability are essential.

Key features

Unconjugated antibodies can be paired with a detection system best suited to the experiment, including fluorescent dyes, enzymes, biotin, nanoparticles, or custom conjugate chemistries.

Maximum experimental flexibility: custom conjugation and assay optimisation
Affinity-purified antibodies: high specificity and reduced non-specific binding
Low background staining: cross-adsorbed antibodies for multiplex applications
Tertiary detection: suitable for signal amplification workflows
Broad species reactivity: antibodies raised against mouse, rabbit, goat, human, rat, chicken, sheep, alpaca, and more
Customisable options: available in multiple fragment formats for specialised experimental requirements

Uses of unconjugated antibodies

Use of unconjugated antibodies_no title

Available formats

Whole IgG Secondary Antibodies
F(ab')2 Fragment Antibodies
Fab Fragment Antibodies
FabuLight™ Fc-Specific Fab Fragments

Structural formats of antibodies and antibody-derived fragments, including IgG, F(ab′)₂, Fab and FabuLight® antibodies

Antibody Fragment strucutres

From left to right:

1. Full-length immunoglobulin (IgG): A conventional Y-shaped antibody composed of two identical heavy chains and two identical light chains linked by disulfide bonds.

2. F(ab′)₂ fragment: A bivalent antibody fragment generated by enzymatic cleavage below the hinge region, consisting of two Fab arms connected by disulfide bonds. The Fc region is absent, but both antigen-binding sites are retained.

3. Fab fragment: A monovalent antigen-binding fragment consisting of one complete light chain and the corresponding portion of one heavy chain, connected by a disulfide bond.

4. FabuLight^TM: A proprietary engineered bispecific antibody format in which a Fab fragment is genetically fused to an IgG molecule, creating a tetravalent construct capable of binding two distinct targets while maintaining Fc-mediated functions.

Color key: Heavy chains, green; light chains, blue; variable antigen-binding region, purple; disulfide bonds, white.

Materials for download

Assay Setup: Sandwich ELISA for Allergy

Direct and Indirect Western Blotting

unconjugated secondary antibodies, antibody fragments, Fab fragments, F(ab')2 fragments, whole IgG secondary antibodies, Fc-specific Fab fragments, secondary antibodies for western blotting, antibodies for immunohistochemistry, immunofluorescence secondary antibodies, flow cytometry antibodies, multiplex immunodetection, custom antibody labeling, affinity purified secondary antibodies, low background secondary antibodies, Jackson ImmunoResearch antibodies, unconjugated antibodies, immunodetection antibodies, ELISA secondary antibodies, microscopy antibodies, FabuLight antibodies

Products

Note: product availability depends on country - see product detail page.

Details	Cat number & supplier	Size	Price
AffiniPure® Goat Anti-Human IgG + IgM (H+L) 109-005-044 · Jackson ImmunoResearch	109-005-044 Jackson ImmunoResearch	2 mg	£150.00 2 mg view
AffiniPure® Rabbit Anti-Dog IgG (H+L) 304-005-003 · Jackson ImmunoResearch	304-005-003 Jackson ImmunoResearch	2 mg	£166.00 2 mg view
Goat Anti-Mouse IgM, µ Chain Specific 115-001-020 · Jackson ImmunoResearch	115-001-020 Jackson ImmunoResearch	2 ml	£117.00 2 ml view
Goat Anti-Mouse IgG, Fc Fragment Specific 115-001-008 · Jackson ImmunoResearch	115-001-008 Jackson ImmunoResearch	2 ml	£104.00 2 ml view
Goat Anti-Rat IgG (H+L) 112-001-003 · Jackson ImmunoResearch	112-001-003 Jackson ImmunoResearch	2 ml	£58.00 2 ml view
Goat Anti-Rabbit IgG (H+L) 111-001-003 · Jackson ImmunoResearch	111-001-003 Jackson ImmunoResearch	2 ml	£58.00 2 ml view
AffiniPure® Fab Fragment Goat Anti-Human IgG (H+L) 109-007-003 · Jackson ImmunoResearch	109-007-003 Jackson ImmunoResearch	1 mg	£132.00 1 mg view
AffiniPure® F(ab')2 Fragment Goat Anti-Human IgG (H+L) 109-006-003 · Jackson ImmunoResearch	109-006-003 Jackson ImmunoResearch	1 mg	£132.00 1 mg view
AffiniPure® Goat Anti-Human IgA + IgG + IgM (H+L) 109-005-064 · Jackson ImmunoResearch	109-005-064 Jackson ImmunoResearch	2 mg	£150.00 2 mg view
AffiniPure® Rabbit Anti-Dog IgG, Fc Fragment Specific 304-005-008 · Jackson ImmunoResearch	304-005-008 Jackson ImmunoResearch	2 mg	£182.00 2 mg view

www.bioscience.co.uk
Sales & Support: +44 (0)1223 316 855