Carol,

You might want to check with the manufacturer of your lenses, but I seem to
recall that lenses that were left in below freezing temperatures, eg left in
the car en route to a demo, were stressed and permanently damaged. This may
be relevant for only some objective lenses.

Pat Masarachia
Bone Biology
Merck & Co.
West Point, PA 19486
215-652-7999

> ----------
> From:         Carol Bayles[SMTP:[log in to unmask]]
> Sent:         Wednesday, June 17, 1998 11:24 AM
> To:   [log in to unmask]
> Subject:      ice cold objectives
>
> 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
>