Traceback identification of plant components in commercial compound feed through an oligonucleotide microarray based on tubulin intron polymorphism

• We developed a microarray for the recognition of plant components in feed.
• Probes were designed on β-tubulin gene first intron sequences.
• Multiplexing capacity is the main advantage of the assay.
• The assay is simple and straightforward.
• Nine out of the ten selected crop species were clearly identified in feed samples.

According to EU Regulations, all components of commercial compound feed need to be declared on the label. Effective protection against fraud requires severe controls based on accurate analytical methods to ascertain what is declared by the producers. The aim of this work was to develop an oligonucleotide microarray for the molecular recognition of multiple plant components in commercial feeds. We tested the potential of the highly polymorphic first intron sequences from members of the plant β-tubulin gene family as a target for plant DNA identification. 23 oligonucleotide capture probes, targeting species-specific intron sequences, were assembled within a low density microarray for the identification of 10 plant species, selected from among those most commonly used in cattle feed formulation. The ability of the array to detect specific components in complex flour blends and in compound feed was evaluated.