Objective: to determine of the activity of antirabic antibodies in blood serum under the different conditions of storage. Materials and methods. Samples of serums from dogs and cats, which got into the laboratory of rabies diagnostics of SSRILDVSE for research. Rabies virus-neutralizing activity of blood serum was tested using the FAVN test. Serum samples were sorted by species, age of animals and titer of rabies antibodies. Aliquots were stored at a temperature of +4 ± 0.5 °C and –20 ± 0.2 °C and exposed to 5‑fold defrosting-freezing. The tests were carried out at the beginning, after 7, 14, 21, 28, 56, 84 days. Results. Period of storage of blood serum at a temperature +4 ± 0.5 °C was 28 days for one of test samples, three of samples were stored for 21 days, but the maximum period for all samples was 14 days. The initial titers of rabies antibodies in sera ranged from 1.95 to 17.74 IU/cm3 and were relatively stable during the period of experiment. In frozen samples of serum the stability of the titer of rabies antibodies was observed throughout the period of experiment. As a result of freezing and thawing of serum, a decrease in the activity of anti-rabies antibodies was observed. Two to three times decrease compared with the initial values was already observed on the 3rd cycle. The initial indicators were at the level of 0.50–0.66–0.87 IU/cm3. On the 2nd and 3rd cycles, the antibody level was 0.38–0.29–0.17 IU/cm3, respectively, which is below the minimum protective titer — 0.50 IU/cm3. Conclusion: The results presented in our study, showed that for serum freezing the temperature of –20 °C is the optimal condition for storage. Freezing samples showed stability in maintaining the level of titers of rabies antibodies. After thawing of experimental samples of serum, they should be stored at a temperature of +4 °C, but not longer than for 14 days. The results obtained indicate that the temperature and duration of storage of serum is an important factor in obtaining reliable results. It should be taken into account by veterinary medicine specialists when transfer samples for research in laboratory
Keywords: serum, rabies antibodies, antibody titer, storage conditions, temperature
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