Researchers from the lab of Marc Friedländer (MBW/SciLifeLab) have discovered that miRNAs – a group of small non-coding RNAs found in all animals and plants – can be used to accurately trace biological samples to their taxonomical origins. This is a challenge with implications for forensics, food quality control and in research settings, where cross-species contamination can compromise results.

MiRNAs are promising biomarkers, since they are abundant and remarkably durable transcripts that can for instance survive thousands of years in permafrost. Besides, many miRNAs are found only in specific groups of animals and plants, meaning that their simple absence or presence in biological samples can unambiguously resolve the species origin.

The researchers have implemented their tracing method as user-friendly and portable software, miRTrace, and demonstrate that it can reveal the primate origins of single human cells, detect parasitic infection of a mouse model, and they provide evidence that ~7% of public miRNA next-generation sequencing (NGS) datasets are contaminated by researcher RNA.

Read the full paper in Genome Biology.