Monoclonal Antibody & BSA Conjugate for Triphenylmethane Dye Residue Detection in Aquaculture ELISA & LFA IVD Development
A malachite green antibody is a monoclonal antibody raised against malachite green — a small-molecule triphenylmethane dye — conjugated to an immunogenic carrier protein (typically BSA) to elicit an immune response suitable for hybridoma production. Because malachite green is a small molecule (MW approximately 365 Da) rather than a protein, it cannot be detected using a sandwich immunoassay; instead, the antibody is used in competitive inhibition ELISA and lateral flow (LFA) formats, where free malachite green in a food sample competes with a malachite green-BSA conjugate for a limited number of antibody binding sites. High residue levels in the sample suppress signal (in ELISA) or suppress the visual test line (in LFA), producing a positive result. This competitive format is what enables the sub-ppb sensitivity required for triphenylmethane dye residue screening in food safety testing programs.
Malachite green has a long history as an unauthorized aquaculture treatment. It was widely used — and in some regions continues to be used illegally — as an antifungal and antiparasitic agent to protect fish eggs, fry, and juvenile stock from fungal infections (particularly Saprolegnia) and external parasites during the vulnerable early stages of aquaculture production. Toxicological studies associating malachite green and its primary metabolite with genotoxic and carcinogenic effects led to its prohibition in food-producing animals across the EU, United States, China, and most other major seafood markets. Because it remains cheap, effective, and readily available, illegal use in some aquaculture operations persists, which is precisely why malachite green residue testing remains a standard component of food safety and export compliance screening programs rather than a legacy concern.
A defining feature of malachite green food safety chemistry is its metabolism: once absorbed into fish tissue, the dye undergoes reduction to leucomalachite green (LMG), a colorless and considerably more lipophilic (fat-soluble) compound. LMG binds preferentially to fatty tissue and is eliminated far more slowly than the parent dye, meaning it can remain at detectable concentrations in fish and shrimp tissue long after malachite green itself has depleted below detectable levels. This metabolic relationship is the reason comprehensive residue-monitoring programs are generally designed to address both the parent dye and its reduced metabolite, rather than screening for malachite green alone — a single-target result can understate the true exposure history of a sample. Sekbio's monoclonal antibody described on this page is raised against and validated for the dominant, oxidized (parent) malachite green form; laboratories building a combined MG/LMG panel should contact our technical team to discuss LMG-specific reagent development.
The export compliance dimension of malachite green testing is significant for producers and IVD kit manufacturers alike. The EU's Rapid Alert System for Food and Feed (RASFF) has repeatedly issued border rejection and alert notifications for malachite green and leucomalachite green residues detected in aquaculture products imported from Asia, and similar import alert mechanisms exist in the US and other major seafood-importing markets. For exporters in Vietnam, China, Thailand, and other aquaculture-producing countries, a documented, sensitive, and reproducible malachite green screening capability is often a precondition for maintaining EU and US market access — making malachite green one of the highest-priority dye residue targets in any aquaculture-focused food safety testing panel.
Matched antibody and hapten-conjugate pair for competitive ELISA and lateral flow malachite green residue screening.
| Reagent | Form Detected | IC50 | ELISA Sensitivity | LFA Sensitivity | Price (1 mg) |
|---|---|---|---|---|---|
| Malachite Green Monoclonal Antibody | Parent (oxidized) dye | 0.5 ppb | 0.05 ppb | 1–5 ppb | $895.52/mg |
| Malachite Green–BSA Conjugate | Coating antigen / test-line reagent | — | — | — | $895.52/mg |
IC50 and sensitivity values from COA release testing in competitive ELISA format against the parent malachite green analyte. Prices are reference list prices per 1 mg; OEM bulk-scale pricing for 10 mg to gram quantities is quoted on request. Contact info@sekbio.com for leucomalachite green cross-reactivity characterization and matrix-specific extraction protocols.
Ultra-sensitive triphenylmethane dye antibody validated for competitive ELISA and LFA development in aquaculture export compliance testing.
Sekbio's malachite green monoclonal antibody achieves an IC50 of 0.5 ppb, giving kit developers a wide working margin below the practical screening thresholds used by aquaculture importers and export testing laboratories. The low IC50 supports both quantitative ELISA determination and confident qualitative LFA screening at the concentrations typically required for compliance testing.
The competitive ELISA format built on this antibody achieves a detection sensitivity of 0.05 ppb — ten-fold below the antibody's IC50 — enabling laboratories to confidently distinguish trace-level contamination from background matrix effects in fish, shrimp, and eel tissue extracts.
The matching colloidal-gold lateral flow strip format delivers visual sensitivity of 1–5 ppb, enabling rapid on-site screening at aquaculture farms, processing facilities, and border inspection points without requiring laboratory instrumentation — critical for high-throughput export compliance screening programs.
Malachite green residue testing is fundamentally an aquaculture problem: the dye's historical use was concentrated in fish farming for disease control during egg and fry production stages. Sekbio's antibody and conjugate pair is developed with this application in mind, supporting extraction and testing protocols for farmed fish (salmon, tilapia, carp, catfish), shrimp, and eel tissue.
Because malachite green metabolizes into the more persistent leucomalachite green (LMG) in fish tissue, understanding this relationship is essential for interpreting screening results. Sekbio can advise on combined MG/LMG panel design so that testing programs are not blind to residues that have already converted to the reduced metabolite by the time of sampling.
Malachite green is a recurring EU RASFF notification category for imported aquaculture products. Sekbio's antibody and conjugate support the sensitive, reproducible screening capability that aquaculture exporters in Vietnam, China, Thailand, and other producing countries need to demonstrate compliance and maintain access to EU and US markets.
MOQ is 1 mg for R&D evaluation, with OEM quantities from 10 mg to gram scale available for ELISA and LFA test kit manufacturing. Sekbio's ISO 13485-certified Shenzhen facility provides quality-assured antibody production with lot COA documentation for kit developers serving global aquaculture export markets.
Beyond the raw antibody and conjugate, Sekbio's technical team supports kit developers with matrix-specific extraction protocol guidance, cross-reactivity characterization, and panel design advice for combined dye-residue and veterinary drug-residue aquaculture screening programs. Explore the complete Sekbio antibody catalog or contact our team to discuss project-specific requirements.
Sub-ppb sensitivity antibody and conjugate for farmed fish, shrimp, and eel dye residue screening in export compliance testing programs.
Malachite green was historically used in freshwater and cold-water aquaculture to protect fish eggs and fry from fungal infection during hatchery and early grow-out stages. Farmed tilapia, carp, and catfish operations in Asia — as well as salmon aquaculture in other regions — remain subject to malachite green residue screening as part of routine quality control and export documentation. Sekbio's antibody and BSA conjugate support competitive ELISA and LFA testing of fish muscle tissue at sub-ppb sensitivity, enabling processors to screen incoming farm-gate stock before it enters the export supply chain.
Shrimp is one of the most heavily monitored aquaculture commodities for dye and veterinary drug residues in EU and US import control programs, given the scale of shrimp exports from Vietnam, India, Thailand, and Indonesia. Malachite green residue testing is typically included alongside nitrofuran metabolite and chloramphenicol screening in comprehensive shrimp export testing panels. Sekbio's malachite green antibody complements these programs, enabling processors and third-party testing laboratories to build multi-analyte aquaculture residue panels on a shared ELISA or LFA platform.
Eel farming, concentrated heavily in East Asia, has historically faced elevated regulatory scrutiny for malachite green and leucomalachite green residues given the species' susceptibility to fungal disease during juvenile stages — a period when illegal malachite green use has been documented. Processors supplying eel to EU and Japanese import markets rely on sensitive, validated screening antibodies to demonstrate residue-free product ahead of shipment and to support internal supplier qualification programs.
Because malachite green and leucomalachite green residues remain a recurring EU RASFF notification category for aquaculture imports from Asia, EU-based import control laboratories and third-party testing services maintain standing screening programs for incoming seafood shipments. Sekbio's antibody and matching hapten conjugate provide the sensitive detection chemistry that ELISA kit manufacturers and LFA strip producers need to serve this testing demand at the ppb sensitivity required to intercept non-compliant shipments before market release.
Technical and commercial questions from food safety IVD developers and aquaculture testing laboratories.
Malachite green is a synthetic triphenylmethane dye historically used as an antifungal and antiparasitic treatment in aquaculture to control fungal and protozoal infections in fish eggs, fry, and broodstock. It is banned for use in food-producing animals in the EU, United States, China, and most other major markets due to genotoxic and carcinogenic concerns identified in toxicological studies. Despite the ban, illegal use persists in some aquaculture operations because malachite green is inexpensive and effective against common fish pathogens, making residue testing a standard requirement for aquaculture exporters and import control laboratories worldwide.
Malachite green is metabolized in fish tissue through a reduction reaction into leucomalachite green (LMG), a colorless, more lipophilic (fat-soluble) metabolite that persists in tissue considerably longer than the parent dye. Because LMG accumulates in fatty tissue and can remain detectable long after the parent malachite green has depleted, comprehensive residue testing programs typically aim to screen for both the parent dye and its reduced metabolite rather than relying on parent-compound detection alone. Sekbio's current antibody is raised against and validated for the dominant/oxidized (parent) malachite green form; contact our technical team to discuss leucomalachite green-specific assay development needs.
Sekbio's malachite green monoclonal antibody achieves an IC50 of 0.5 ppb in competitive ELISA format, with a validated ELISA detection sensitivity of 0.05 ppb. The matching colloidal-gold lateral flow (LFA) rapid test strip format achieves a visual sensitivity of 1–5 ppb, suitable for on-site or field screening at aquaculture farms, processing plants, and import inspection points.
The antibody is intended for aquaculture and seafood matrices where malachite green use has been historically documented, including farmed fish (salmon, tilapia, carp, catfish), shrimp, and eel. These are the species and matrices most frequently flagged in EU RASFF (Rapid Alert System for Food and Feed) border rejection notifications for malachite green and leucomalachite green residues.
The EU RASFF system has repeatedly issued border rejection and alert notifications for malachite green and leucomalachite green residues detected in aquaculture products imported from Asia, reflecting continued illegal use in some fish and shrimp farming operations despite the compound's ban. This regulatory scrutiny makes malachite green one of the standard screening targets required for aquaculture exporters in Vietnam, China, Thailand, and other major seafood export markets seeking to maintain EU and US market access.
Sekbio supplies the malachite green monoclonal antibody and its matching malachite green-BSA conjugate at a reference price of $895.52 per mg for either reagent. MOQ is 1 mg for R&D evaluation, with OEM bulk quantities from 10 mg to gram scale available for ELISA and LFA test kit manufacturing. Contact info@sekbio.com for a formal quotation and current lead times.
Yes. The antibody and its BSA conjugate are validated for both competitive ELISA (microplate) format and colloidal-gold lateral flow (LFA) rapid test strip format. In ELISA format, this reagent pair achieves 0.05 ppb sensitivity suitable for laboratory quantification. In LFA format, the antibody is conjugated to colloidal gold and the malachite green-BSA conjugate is striped on the nitrocellulose test line, achieving 1–5 ppb visual sensitivity for rapid qualitative screening.
Malachite green testing is often paired with other aquaculture-relevant residue targets in a shared ELISA or LFA platform.
AOZ, SEM, AMOZ, and AHD metabolite antibodies for the classic nitrofuran residue panel used alongside malachite green in shrimp and aquaculture export testing. See the Nitrofuran Metabolite Antibody data sheet for full IC50 and sensitivity specifications.
Chloramphenicol and florfenicol/thiamphenicol residues are commonly co-tested with malachite green in aquaculture export compliance panels. Review the Antibiotic Residue Antibody hub page for the full veterinary drug residue antibody catalog.
Browse the complete Sekbio antibody product catalog or contact our team to discuss multi-target aquaculture residue panel development.
Request a malachite green antibody evaluation kit, hapten conjugate sample, or discuss OEM ELISA and LFA kit development support.