Difficulties in the evaluation of hybridisation signals in samples with mould infection. Autofluoresence of hyphae (a-d) or surrounding tissue (e-h) in two tissue specimens from patients with invasive aspergillosis. Hybridisation with DAPI and eukaryotic universal probe (univ-SSU labelled with FITC). DAPI channel (first column), FITC-channel (second column), Cy-3 channel (third column). Fusion picture DAPI and FITC channels (last column).