include the consistency of DNA from any part of the plant, and
the fact that DNA is not affected by the age of the plant or the
growing/harvest conditions [12]. The amount of plant material
required for the analysis is negligible, and resolution of identity
to the species level is easily achievable [7,10,11,13]. However, it
is known that medicinal plant products may not contain high
quality DNA, as damage can occur during the manufacturing
and storage processes [8]. So the question remains as to how
applicable these techniques are to over-the-counter products.
This study aims to answer this question by applying a
DNA-based PCR test to attempt to detect the presence of
H. perforatum in commercial St. John's Wort products. As a
market leader, St. John's Wort is widely available in several
different forms including capsules, tablets and tinctures, making
it an ideal pilot study. This test has been specifically designed to
account for degraded DNA by relying upon a short amplicon of
just 80 bp.