Search the CONFOCAL archive at
http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal

Hi All,

[log in to unmask] wrote:

>Search the CONFOCAL archive at
>http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
>
>A problem with using large microspheres is that their refractive index is higher than that of the surrounding medium and therefore if you wish to extract a PSF from a large microsphere the distortion due to this RI mismatch would need to be taken into account - I assume that with small microspheres this can be discounted.
>
>
Yes. Also, since the photon yield of much smaller beads like the 170nm
diameter beads from Molecular Probes is quite sufficient to measure the
PSF of a well aligned confocal microscope, it is not necessary to deal
with the hazards of micron sized beads.

>Quantum dots would seem to be ideally suited for generating situ PSFs, provided they can be immobilised.
>
>
Agreed. Even with small beads one needs to correct for non-homogeneous,
even gaps in the spatial frequency content in order
to 'distill' the PSF -- not that that is really a problem. Quantum dots
would allow a more direct measurent though.

-- Hans