Abstract
The Hawaiian strain of dengue virus was purified from developing chick embryos and suckling mice brains with protamine clarification and ultracentrifugation. Twenty per cent solution of developing chick embryos infected was made with pH 8.5 Ringer solution and extracted in the cold for 3 days to disintegrate normal component. However, in the case of mice brains ten per cent suspension was prepared with double distilled water and immediately subjected to the treatment with protamine sulfate (salmine). Dengue virus remained in protamine supernate as expected because of its small size, and was centrifuged at high speed, approximately 85, 000g for 60 minutes.
Log of LD 50/g nitrogen of a final purified material, suspension of pellets in buffered saline, from developing chick embryos was 11.4 while that from suckling mice brains 13.3. (Refer to paege. 6-11)
Acknowledgement
This study was carried out at the Department of Bacteriology and Parasitology, University of Chicago in 1951 under the aid of Mc Cormick Fund. The author wishes to thank Dr. Robert Rustigian for his helpful advice and greatest support.
