Collection tubes with or without gel separator did not interfere with detection of rubella virus antibodies IgM and IgG.

Rubella infection is an exanthematic disease, with high prevalence in the adult population. The only modality of disease that causes serious consequences is congenital rubella syndrome (CRS), which happens when a pregnant woman seronegative to rubella virus acquires the infection during early pregnancy. Due to the lack of signals and characteristic symptoms of disease, diagnosis of rubella is based essentially on laboratory tests: antibodies detection and/or virus isolation. Results of serologic tests should always be interpreted with caution, because they can be affected by the quality of blood samples, processing and storage of sera, the equipment and reagents used to perform tests, and finally by the technical expertise and training of biologists. The collection tubes with gel seem to facilitate serum separation, but on the other hand gels can retain and consequently decrease antibody titers. Therefore, we decided to investigate whether the use of collection tubes containing gel separator might interfere with rubella virus antibody detection in blood samples from children. We did not observe statistically significant differences with respect to rubella virus antibody detection (immunoglobulin M [IgM] and immunoglobulin G [IgG]) for samples collected in tubes with or without gel separator, from the two evaluated manufacturers. (c) 2007 Wiley-Liss, Inc.