I'd like to prepare 2.5% glutaraldehyde/2% paraformaldehyde in 0.1 M sodium cacodylic acid. We can buy this pre-made but we only need to use low volume at a time so buying pre-made buffers (minimum order of 100 mL) is not cost-effective. So I plan to prepare this buffer myself and just store by freezing. Can I do this? Will this affect the property of the buffer? Any tips for storing this long term are highly appreciated.