A user wants to look at the ionic interactions of a solution polystyrene
beads and needs a matrix to immobilize them in for optical sectioning on
the confocal and then will measure the distances between them.  The matrix
cannot be more ionic than water, which eliminates gelatin and agar, and
also needs to have the same density as water, so the beads do not sink.
He is considering using ice, quickly frozen to avoid uneven expansion.  He
has a small chamber that he can maintain at 0C (or lower) and he can blow
nitrogen over it to eliminate condensation.   He wants to put immersion oil
directly on the ice, with no cover slip inbetween.   I have several
questions:  What happens to immersion oil at 0 degrees C?  Can this
temperature be damaging to the objective?  Does anyone have any other ideas
for a matrix that will perform as required?  The polystyrene beads were
chosen because they come in micron sizes and have a charge in solution.
Other beads with these properties may be considered.

Thanks,

Carol Bayles

Carol Bayles                                                    607-254-4860
Microscopy and Imaging Facility         607-254-4847  fax
BioResource Center                              [log in to unmask]
160 Biotech Bldg
Cornell University
Ithaca NY 14850