ObjectiveTo analyze the effects of ultrasonic homogenization on the stability of Sendai virus (SeV) in ELISA. MethodsThe SeV amplified in BHK-21 cells was purified by differential centrifugation, and then homogenized by ultrasonication. The ultrasonic-treated SeV antigen and the untreated antigen were coated in the wells of ELISA plates. The coefficients of variation (CV) between the two kinds of plates were compared by testing SPF mouse serum and SeV-immunized serum. Resultsthe CV of gradient diluted Sendai virus-immunized serum was between 1.97% to 6.02% in untreated antigen coated plates and 0.53% to 2.26% in ultrasonic-treated antigen coated plates. The CV of SPF sera was higher than that of SeV-immunized serum. The CV of all the tested samples in ultrasonic-treated antigen coated plates was lower than that in the untreated antigen coated plates. ConclusionUltrasonic treatment can homogenize the SeV antigen and improve the SeV antigen stability in ELISA.