Exactly what sorts of tests are you preserving them for?

I have experience with short/medium term preservation of buds/anthers for cytogenetic microscopy (ferric propionic acid + EtOH, followed by storage in EtOH), but such samples would probably not be appropriate for some downstream techniques.

If that doesn't work, how about flash-freezing with liquid nitrogen?

Also, what species are you working with?

Hello Jack,

Thanks for your kind reply. I am currently working with orchid species and want to localize the histone chromatin modification for which Paraformaldehyde is used generally for fixing the samples followed by squash preparation. but I want to preserve such buds without degrading histone proteins. Flash-freezing with LN2 may change the protein confirmation and affect the precise identification of chromatin environment. 

Ah, thanks! That's beyond my expertise. However, I look forward to hearing the solution to this interesting problem!

Thanks Saumil for your suggestion. Such Carnoy's fixation is fine for conventional studies but not at all suitable for immune-staining. Thanks anyway!