A comparison of methods used to measure the infectivity of prions reveals an efficient and cost-effective alternative to time-consuming conventional techniques. The work, reported in a paper published in Nature Communications represents the first side-by-side comparison of two widely known techniques for measuring prion infectivity. Prions are the infectious agents that cause scrapie in sheep or Creutzfeldt-Jakob disease - sometimes know as mad cow’s disease - in humans. The traditional method for estimating prion infectivity involves the injection of various dilutions of prion proteins into animals. The major drawback of this method is that a waiting time of up to several years is needed to see which animals develop the disease. A widely used method called protein misfolding cyclic amplification with beads (PCMAb) can deliver results within days. Ilia Baskakov and his team compared a modified version of PCMAb with the conventional method. This comparison revealed that PCMAb can not only be faster but also more precise, as PCMAb detected samples with low infectivity that were undetectable with the traditional techniques. The authors also note that PCMAb has ethical advantages over conventional methods as the technique does not involve animals.