A good and reliable reference database is essential for metabarcoding. In addition, eDNA metabarcoding provides a fundamentally different type of data; because eDNA does not necessarily originate from the sampling location, the geographical scale must be further defined.

With DNA barcoding, animal and plant species are identified on the basis of DNA. In animals, for example, this is often the CO1 gene. Determining the order of the base pairs of this DNA is called barcoding, with the end product being the barcode. By comparing this barcode with existing barcodes in a reference database it is possible to obtain a fast and reliable identification.

With metabarcoding, multiple pieces of DNA are read simultaneously. The end result is a list of species present in a sample. This method regularly uncovers striking biodiversity that would otherwise require a lot of effort with traditional methods.