pollen storage and materials
ConroeJoe@aol.com (Fri, 12 Aug 2005 14:23:14 PDT)

In a message dated 8/12/2005 10:37:30 AM Central Daylight Time,
pbs-request@lists.ibiblio.org writes:

Hi,

I have to agree that my best results with any storage of pollen or seeds (if
they will store at all) is when I have used materials that truly dessicant and
containers which are airtight.

So, drierite works much better for me (over several years) than silica beads.
Also, ziplock bags don't compare to tightly closed baby food jars; ziplock
bags leak humidity over several months. I mix a bit of the color-change
indicator type (of drierite) mixed with the less expensive white form. This way, I
can use "essentially" airtight containers but always use see-through
containers and keep tabs on the drierite. Baby food jars work OK for me, but for long
term storage (things I'm not sure if I'll get back to in a year or so), I use
containers that have very good seals (fruit jars sometimes).

If the drierite starts to turn pink I know that something is wrong, and I
replace the container and add new drierite.

Sometimes, I'll even dry seeds or pollen over drierite. I place air-dried
materials over several inches of drierite and leave it for 2-3 weeks. Even if
the drierite does not change to pink, I still retrieve the biological materials
and put them over a new layer of drierite in a new container. Houston and
humidity, and ways to deal with such, are just ways of life.

One note about blue drierite: you can reuse it endlessly, just bake it for
2-3 hours at 250 in the oven. But, there is a trick. You have to bake it in a
thin layer, about 1 particle thick in order to regain the nice blue color,
and hence the useful color-change feature. I am not sure, but I think it has to
do with oxygenation and heat. If you bake the particles in a layer of 1/2 or
so, many of them turn lavender--not blue. In a container it is sometimes
difficult to tell lavender from pink, and so the color-change wetness indicator
is less effective. But blue drierite costs more, so I mix it about 10% with
regular white.

I think silica gel beads would work very well if the goal is to store pollen
for 1-2 years. I've just never tried because drierite is a better dessicant
and I have just always used it.

Cordially,

Conroe Joe