The effect of serum storage factors influencing the reactivity of antibodies in serodiagnostic tests

Abstract EN

To investigate the effect of different serum storage methods on reactivity of bovine Brucella antibodies in serodiagnostic tests, sera were collected from Brucella infected cattle and stored either in a refrigerator at 4˚C or in a deep freezer at -20˚C mean while reference serum samples were stored at 4˚C, -20˚C and -80˚C.

Monitoring of the Brucella antibody activity in stored samples, was performed by Slow Agglutination Test (SAT) on monthly basis for six months and results obtained were analyzed in three dimensions.

First, between different time intervals, second, between different storage temp-eratures and finally between collected sera and reference sera samples.

Analysis of the results revealed a significant reduction in titer of Brucella antibodies in sera stored at -20˚C after two months of storage, whereas no significant difference could be detected in antibodies titer for up to four months of serum storage at 4˚C, meanwhile reference samples showed stability in titer of Brucella antibodies when compared with collected serum under the same storage temperatures.

It was concluded that the effect of storage temperature is more or less affected by quality of serum.

Since high quality serum is the cornerstone in sera-epidemiological studies and diagnosis, we recommended the necessity of sterilization of serum by filtration.

Additionally, the constancy of cooling tempera-true and the avoidance of refreezing and thawing during storage should be considered in order to get accurate results from serum samples.