A Comparative Study of the use of Dried Blood on Filter Papers and Serum Samples for Serodiagnosis of Anaplasmosis

Abstract

A study was conducted to compare the suitability of blood collected on filter papers with corresponding
fluid serum samples in serodiagnosis of bovine anaplasmosis using DOT-ELISA, RCAT and Western
imunobtotting. Serum was obtained from blood collected by jugular venipuncture of288 heads of
cattle and stored at -70 °C. About 0.2 ml of the corresponding blood sample was applied and dried on
filter paper (Wbatman No.1) after collection in duplicates. One of the duplicates was stirred at room
temperature and the other at 4°C. Subsequently, sera were eluted from the dried blood samples on the
filter paper with a solution of 1.8 ml PBS Tween 20% at pH of7.2 to give a dilution of 1:100. Antigens
were prepared as described by Montenegro-James et al (1988) and analysed by DOT-ELISA and Western
immunoblot at dilutions ranging from 1:25 to 1:200. Results showed that dried blood samples on
filter paper were suitable for sero-epid€miological studies of bovine anaplasmosis and storage at room
temperature for 6 months did not affect reactivity.