Information from: R. H. Kokernot, University of Texas, School of Public Health, P.O. Box 20186, Houston, Texas 77025, 14 August 1969.
Antigenic group: Ungrouped.
Original source: Isolated by R. H. Kokernot and colleagues at the University of Illinois, Urbana, Illinois, from a single nymphal Amblyomma americanum (Linn.) removed from a woodchuck (Marmota monax) captured 20 June 1967 in the Land Between the Lakes area, western Kentucky, Lat. 36° 50′ N, Long. 88° 00′ W. Habitat: Oak-hickory forest, border of abandoned fields and deciduous forest. Storage: Tick stored over solid CO2 until tested.
Method of isolation in laboratory: Nymph ground in 2.5 ml of 20% normal rabbit serum in saline solution containing penicillin and streptomycin. Inoculated 0.02 ml in 1- to 2-day-old mice on 8 September 1967.
Validity of isolation: Virus reisolated from original tick suspension.
Properties of virus: Physical: Filterable through Seitz asbestos pad and Millipore 220 nm; drop in titer with Millipore 100 nm; not filterable through 50 nm APD.