2F4 Monoclonal Antibody —
Detecting calcium-cross-linked pectin
in plant cell walls
A conformation-specific probe for egg-box homogalacturonan. Widely used in immunofluorescence, ELISA and biochemical assays. Developed by Fytofend, pioneered by Prof. Pierre Van Cutsem.
2F4 publication
Immunofluorescence, ELISA, Western blot, Immunohistochemistry
epitope recognition
egg-box conformation
A molecular probe for
pectin architecture in plant tissues
The 2F4 monoclonal antibody is a widely used molecular probe for studying the structure and organisation of pectin in plant cell walls. Pectins are complex polysaccharides forming a major component of the primary cell wall and middle lamella, where they play key roles in cell adhesion, wall porosity and mechanical strength.
Among the different pectic domains, homogalacturonan (HG) is the most abundant — composed of linear chains of α-(1→4)-linked D-galacturonic acid residues. These can be modified through methyl esterification and acetylation, which strongly influences the structural and mechanical properties of the plant cell wall.
The particular interest of 2F4 lies in its ability to recognise a specific supramolecular organisation of homogalacturonan, rather than simply detecting the presence of the polymer itself. This conformation-dependent specificity makes it uniquely powerful for research on plant development, cell mechanics and pectin remodelling.
The egg-box structure —
How 2F4 recognises calcium-cross-linked HG
A defining property of 2F4 is its specificity for calcium-cross-linked homogalacturonan. This supramolecular architecture — known as the “egg-box” — is formed only when specific conditions in the plant cell wall are met.
Calcium ion cross-linking
Two parallel HG chains align and are stabilised by Ca²⁺ ions coordinating the negatively charged carboxyl groups of galacturonic acid residues — creating a rigid pectic network.
Conformation-dependent epitope
2F4 does not bind isolated HG chains. It exclusively recognises the supramolecular arrangement formed through calcium bridges — making it a precise structural probe, not a simple polymer detector.
Role of methyl esterification
The 2F4 epitope requires low methyl esterification. When PMEs remove methyl groups, free carboxyl groups become available for calcium coordination, enabling egg-box formation and antibody binding.
Detection indicates wall reinforcement
Calcium-cross-linked HG domains are enriched in the middle lamella, cell junctions and regions requiring mechanical stability — making 2F4 labelling an indicator of structural cell wall integrity.
Three major fields of application
The 2F4 monoclonal antibody is used across developmental plant biology, biochemical analysis and cell wall mechanics research — wherever calcium-pectin interactions need to be visualised or quantified.
Immunolocalisation
High-resolution spatial mapping of egg-box pectin domains in plant tissues using immunofluorescence microscopy and immunogold labelling.
- Embryogenesis & seed coat formation
- Stomatal development
- Shoot apical meristems
- Specialised extracellular matrices
Biochemical detection
Quantitative and semi-quantitative detection of calcium-cross-linked HG in extracted pectin fractions and plant-derived biomaterials.
- ELISA-based detection
- Dot blot analysis
- Pectin binding assays
- Food system & biomaterial studies
Cell wall remodelling
Tracking dynamic changes in pectin cross-linking during tissue development, fruit maturation and environmental responses.
- Fruit softening & ripening
- PME enzyme activity studies
- Calcium availability mapping
- Tissue cohesion & mechanics
Specificity, usage & interpretation
🎯 Using 2F4 alongside complementary probes
2F4 is frequently used in combination with other anti-pectin monoclonal antibodies to provide a complete picture of HG organisation:
- JIM7 — detects highly methyl-esterified HG domains
- JIM5 — recognises low-esterified HG regions
- 2F4 — specifically detects calcium-cross-linked (egg-box) HG
Used together, these probes allow researchers to map the full esterification and cross-linking landscape of pectin within a tissue section.
⚠️ Experimental interpretation
Because the 2F4 antibody recognises a calcium-dependent conformation, results may vary depending on several experimental parameters:
- Calcium concentration in sample buffer
- Sample preparation and fixation method
- Degree of pectin methyl esterification
Absence of 2F4 labelling does not indicate absence of pectin — it indicates that pectin is not present in the calcium-cross-linked configuration recognised by the antibody.
Foundational publications
The foundational 2F4 publication has been cited over 288 times across plant biology, biochemistry and food science. Below are the key foundational references.
Case studies
Proud of your results? Share your publications where 2F4 was used — we’ll gladly add them to our list of case studies. Contact us at antibodies@fytofend.com
Everything you need to know
about the 2F4 antibody
Explore further
COS-OGA — the active substance behind Fytosave®
Derived from the same pectin and chitosan research, COS-OGA is Fytofend’s patented biocontrol active substance.
Explore COS-OGA →Fytosave® — Biocontrol for powdery mildew
The agricultural application of Fytofend’s oligosaccharide research — zero residue biocontrol for crops.
Discover Fytosave →Order the 2F4 antibody or share your publication
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Get in touch →Interested in the 2F4 antibody?
Contact our team to order, request a datasheet, or discuss your research application. We also welcome publication submissions for our case study list.
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