id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-335482-nx7odchj	Makino, Shinji	Defective interfering particles of mouse hepatitis virus	1984-02-29		.txt	text/plain	3840	210	60	We have observed marked reduction of infectivity in the course od serial undiluted passages of JHM virus in DBT cell culture. To avoid contamination of the standard virus stock with DI particles, plaque purified MHV (JHM strain) (Hirano et aL, 1981; Makino et al, 1983) was propagated on DBT cells at a multiplicity of infection (m.o.i.) of 0.0002 and at 15 hr postinfection (p.i.) culture fluid was harvested and clarified by low speed centrifugation. Preparation of the Standard JHM Virus for Interference Assay JHM virus was propagated on DBT cells after infection at an m.o.i. of 1.0 and was harvested at 14 hr p.i. The culture fluid was clarified by centrifugation at 8000 rpm for 30 min. To determine if the reduction in the yield of infectious virus was due to the presence of DI particles, a'n interference analysis was performed with several culture fluid samples at different passage levels.	./cache/cord-335482-nx7odchj.txt	./txt/cord-335482-nx7odchj.txt