Malachite Green Found in Live Groupers Imported from Taiwan

Malachite green is a triphenylmethane dye used in the aquaculture industry to treat fungal infections however, it has been banned in many countries including China since 2002. Research suggests that it is harmful to human health causing toxic effects including carcinogenesis, mutagenesis, teratogenicity and respiratory toxicity.

This year, Taipei Times reported that two fish farms in Pingtung County within China, are being investigated due to the discovery of illegal veterinary drug residues present in imported live groupers from Taiwan. The Chinese General Administration of Customs stated that it had identified two prohibited substances including malachite green and crystal violet in live groupers. Resultantly, the Taiwanese authorities have suspended trading permits preventing export operations of the farms until the issue is dealt with further.

Randox Food Diagnostics have developed the Malachite Green FAST ELISA which can be used to screen 5 compounds including malachite green, leucomalachite green, crystal violet, leucocrystal violet and brilliant green. Up to 40 samples can be analysed within 90 minutes giving the user accurate results in a short time frame. This ELISA is validated for testing catfish, prawn and shrimp.

Randox Food Diagnostics also offer the Antimicrobial Array III for testing AOZ, AMOZ, AHD and SEM. Using Biochip Array Technology users can test multiple drug residues from a single sample in a variety of aquaculture species, with unrivalled detection limits and excellent specificity.

For more information on our screening solutions for seafood testing, please contact us via email:

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