The aim of the present study was to compare the ability of the commercially available portable test system (PTS^<TM>) to detect endotoxin activity in bovine serum, with that of the traditional LAL-kinetic turbidimetric (KT) and chromogenic (KC) assays. Prior to testing, serum samples, which were obtained from endotoxin-challenged cattle, were diluted 1:20 in endotoxin-free water and heated to 80°C for 10 min. The performance of the PTS^<TM> was not significantly different from that of the traditional LAL-based assays. The results using PTS^<TM> correlated with those using KT (r^2=0.963, P<0.001) or KC assays (r^2=0.982, P<0.001). Based on these findings, the PTS^<TM> could be applied as a simplified system to assess endotoxin activity in bovine serum.