The samples were analysed by conventional histology using haematoxylin–eosin (HE) staining of sections of paraffin-embedded tissue. Immunohistochemistry was performed as described using a mutation specific monoclonal antibody for detection of the H3F3A G34W mutation (Anti H3.3 G34W clone 31-1145-00; RevMab Biosciences, San Francisco, CA, USA; dilution 1:400); for detection of proliferation indices the Ki-67 antibody (M7240, Dako, Glostrup, Denmark; dilution 1:200) was applied11 .
The alkaline phosphatase/RED detection system (Dako) was used for immunohistochemistry on formalin-fixed and paraffin-embedded tissue via the avidin–biotin-complex-method. The samples were pseudonymized according to the German law for correct usage of archival tissue for clinical research. The research was approved by the local ethics committee of the University of Ulm (reference 369/17) and was in compliance with the ethical principles of the World Medical Association Declaration of Helsinki. Informed consent was obtained from all patients.
The alkaline phosphatase/RED detection system (Dako) was used for immunohistochemistry on formalin-fixed and paraffin-embedded tissue via the avidin–biotin-complex-method. The samples were pseudonymized according to the German law for correct usage of archival tissue for clinical research. The research was approved by the local ethics committee of the University of Ulm (reference 369/17) and was in compliance with the ethical principles of the World Medical Association Declaration of Helsinki. Informed consent was obtained from all patients.