The potential of Cartapip™, an albino Ophiostoma piliferum, as a biocontrol agent against sapstain in logs has been tested in Germany. To detect the albino strain in field-tested wood, the usefulness of the β-tubulin gene as a target region for developing PCR-based assays was evaluated with 102 strains of O. piliferum and 31 strains of other wood-inhabiting species. A partial β-tubulin gene sequence of O. piliferum strains from different geographic origins was amplified by PCR and analyzed by restriction enzyme digestions and DNA sequencing. Variation in size and nucleotide sequences was found in intron regions indicating that intraspecific variation is present in the β-tubulin gene. Consequently, β-tubulin gene-derived PCR methods using PCR–RFLP patterns generated by HinfI and SpeI and sequence-specific primers Cat1 and Cat2, were developed and their specificity for Cartapip™ was accessed with field-tested logs and lumber. The β-tubulin gene-based PCR methods were found to be valuable tools for rapid and reliable identification of Cartapip™ in field-tested logs and lumber in Germany. Specificity tests against other wood-inhabiting species and wild type O. piliferum strains from diverse nations showed that the Cat1 and Cat2 primers have potential to be used in other European countries, New Zealand, Alberta and British Columbia.