The plate was cut into two pieces
(10 × 10 cm) and one half was derivatized with p-anisaldehyde
sulphuric acid. To maintain the plate coating during incubation with
blood-gelatin, wetting the plate in 0.5% PIBM solution (w/v) for 1 min
was mandatory (Ishikawa & Taki, 2000; van Die, van Stijn, Geyer, &
Geyer, 2010).