Philip Barren writes: > > I am trying to look at the binding of virus to cells. Does anyone >have any thoughts on doing this without using antibody to label the virus?? >I want to effect the virus/cell binding as little as possible. > At least some viruses (depending on which nucleic acid they have and how tightly packed it is) can be labeled with nucleic acid dyes. The dimeric dyes (YOYO-1, TOTO-1, etc.) have high enough affinity constants that they won't come out of the viruses. This approach was used by Curtis Suttle to "phage type" straines of Synechococcus using labeled bacteriophages and fluorescence microscopy (Hennes KP, Suttle CA, Chan AM: Fluorescently labeled virus probes show that natural virus populations can control the structure of marine microbial communities. Appl Environ Microbiol 61:3623-7, 1995); using samples he sent me, I was able to detect both viruses bound to the cyanobacteria and (probably) single labeled virions using a high-sensitivity Cytomutt, but we never got around to publishing the observations. Daniel Vaulot and coworkers did the same trick more recently and did publish, also in Applied and Environmental Microbiology, within the past few months; they were detecting free virions by YOYO-1 fluorescence using a FACScan (or maybe a Calibur). Since the nucleic acid dye should not be bound to the surface of the virus, the binding of labeled viruses to cells shouldn't be affected. In the early 1980's, Ken Rosenthal (a virologist now at Northeastern Ohio Universities college of Medicine, not the immunologist from McMaster) labeled EBV with cyanine dyes (by growing it in cells loaded with dye) to look at binding by flow cytometry (I don't recall whether we published this or not); the nucleic acid labels give substantially larger fluorescence signals. -Howard
This archive was generated by hypermail 2b29 : Wed Apr 03 2002 - 11:53:15 EST