RESUMEN
Aim To investigate the slope ratio method for the determination of anticoagulant activity of leeches. Methods Three batches of leeches, four groups of Japanese medical vermiculite yinpian and fifteen groups of leech preparations were chosen, with contrast medicinal leeches herbs and Philippine cattle leech contrast medicinal materials, and different concentrations of leaching solutions were prepared in parallel. APTT value was determined after anticoagulant activity was determined by slope ratio method for the joint validation of laboratory, intermediate precision and accuracy between the linear range. Results The slope ratio method was accurate and accurate in the determination of anticoagulant activity of leeches, with linearity between 64% and 156% relative titer level. Conclusion Slope ratio method can be used to determine the anticoagulant activity of leeches.