EN
The presence of parasites and bacteria was controlled in mice maintained in open conventional conditions. Moreover, an enzyme-linked immunosorbent assay (ELISA) was applied for the detection of antibodies to Mycoplasma pulmonis and to viral infections (Ectromelia virus and Sendai virus) in the sera of these mice. For ELISA tests the kits offered by University Hospital Nijmegen, the Netherlands, were used. Forty mice were controlled bacteriologically and 39 mice parasitologically. The ELISA test for the presence of Ectromelia virus was performed with 15 sera, for Sendai virus - with 27 sera and for Mycoplasma pulmonis with 12 sera. The results obtained allowed us to conclude that laboratory mice bred in open conventional conditions at the Cancer Center in Warsaw can be classified as CV-II (Conventional-II).