For single-species studies, we use qPCR, which is fast to perform as it does not require DNA sequencing. The qPCR process uses a unique species-specific primer to amplify the target DNA in your sample.
Because the primers are designed to only match the DNA of the target species, the qPCR reaction will only produce successful DNA amplification if the target’s DNA is present in the sample. The qPCR test simply measures the amount of DNA to determine whether amplification has taken place and infers species presence on that basis. Based on how quickly the amplification occurs, it is also possible to estimate the amount of the target’s DNA that was in the sample. This may be loosely related to the species’ abundance in the environment depending on the type of species and ecosystem.
We use qPCR for single-species eDNA surveys of Great Crested Newts and other aquatic organisms such as crayfish, eels and mussels (see full list here). Our lead scientist, Dr Cuong Tang, demystifies qPCR in our webinar titled “Your GCN eDNA Toolkit with NatureMetrics”.