Assay of variola virus by the fluorescent cell-counting technique.

Quantitative Assay of Psittacosis Virus by the Fluorescent Cell-counting Technique.

The studies described here indicate that the fluorescent cellcounting technique provides a rapid, precise, reproducible, and sensitive procedure for the assay of infective particles of psittacosis virus. The efficiency of virus adsorption onto coveralip cultures of McCoy cells was markedly increased by the use of centrifugal force; assay values were 1.0 log higher than those obtained after stat...

Visualization of Horse Sickness virus by the Fluorescent antibody technique

Primary virus-cell interactions in the immunofluorescence assay of Venezuelan equine encephalomyelitis virus.

The conditions under which Venezuelan equine encephalomyelitis (VEE) virus attached to host cells markedly influenced the assay of virus by the fluorescent cell-counting technique. When virus inoculum was centrifuged onto McCoy cell monolayers, approximately 97% of virus was attached to cells within 10 min, in contrast to 34% after stationary incubation at 35 C for 2 hr. Maximal binding of viru...

Development of a High-Content Orthopoxvirus Infectivity and Neutralization Assays.

Currently, a number of assays measure Orthopoxvirus neutralization with serum from individuals, vaccinated against smallpox. In addition to the traditional plaque reduction neutralization test (PRNT), newer higher throughput assays are based on neutralization of recombinant vaccinia virus, expressing reporter genes such as β-galactosidase or green fluorescent protein. These methods could not be...

Quantitative assay of interferon by the immunofluorescent cell-counting technique.

A rapid, quantitative assay of interferon was developed, based on the reduction of the number of virus-infected cells by dilutions of interferon. Infected cells were enumerated by fluorescent cell-counting 24 hours after challenge of interferontreated McCoy cover-slip cell monolayers. A quantitative linear relationship between the reduction of fluorescent cells and dilutions of interferon was d...