Hi.Nothing but pure, compacted pollen goes into the container and there's absolutely no air inside the container.
I would advice not to pack pollen too tightly in vials if you’re not sure it is very dry because it might clump and when it is clumped up the moisture in it might ruin pollen.
I’m sure you guys can guess the reason i know this..
It’s good to fill the vials so that they don’t have much air in them but don’t pack it too tightly. Summer or more humid season is when pollen will hold more moisture in it and it is easy to clump it and ruin it if you pack it in too tightly.
I drop some silica pellets in to the plastic vial before i put them in the freezer