LONDON – Bio-Techne Corp. said it will buy liquid biopsy specialist Exosome Diagnostics Inc. for $575 million, of which $325 million will be paid up front, with $325 million to come on reaching certain milestones. The deal will give Bio-Techne ownership of a marketed urine-based test, Exodx prostate intelliscore (EPI), which is used in weighing the need for a prostate biopsy in cases of ambiguous prostate-specific antigen test results.