Use of the Nobuto blood-sampling paper strip for Newcastle disease serology

Dried whole blood collected by the paper-strip method of Dr. Kenzo Nobuto was evaluated for use in the Newcastle disease hemagglutination-inhibition (HI) test. When dried blood on the Nobuto strip was eluted in 1.0 ml of diluent, the resulting HI titers were similar to titers obtained with sera diluted 1:10. Both storage time and temperature influenced the stability of HI activity in dried blood, though the influence was minimal and is considered to have little significance in diagnostic serology, The advantages of this method of blood collection for Newcastle disease HI tests are discussed.