[RASMB] determination of phage particle concentration

[Borries Demeler]

I wonder if one could mitgate the problems with light scattering by
preparing a known, significant dilution, staining with sybrgreen
and looking at fluorescence intensity in a velocity experiment.
Sybrgreen bound to DNA is very sensitive and this can be done at very
low concentration.

We have done this with good success using the Aviv fluorescence machine
to measure phage aggregation behavior. Dilutions provided linear changes
in fluorescence intensity. Sybrgreen seems to have no problem leaking into
the phages we investigated and lights them up like a christmas tree. One
issue though is that one would need some standard, and I am not sure how
to get this. At the very least one could use this to determine if there
is leaked DNA in the prep or other contaminating DNA, and sybrgreen has
a very low background.

Serwer P, Hayes SJ, Thomas JA, Demeler B, Hardies SC. Isolation of novel
large and aggregating bacteriophages. Methods Mol Biol. 2009;501:55-66.

Regards,
-Borries