Two separate testing methods were developed using
paper, each using different principles regarding the interactions
of the analytes, samples and washing method.
One method follows the principles of chromatography,
allowing the washing solution to elute unbound blood
cells laterally along the paper structure (wicking). This
method was used for ABO and RhD groups [11]. The second
uses the flow-through method [12, 18, 19], which
washes through the paper, rather than along, utilizing a
filtration mechanism. While each method has been successful
when testing ABO and RhD blood types, this is the
first report testing paper diagnostics for the detection of
blood group phenotypes other than ABO and RhD using
both methods.