[ccp4bb] suggestions for cryoprotectant

[Deepak Thankappan Nair]

Hello,
Does anybody know what would be a good cryoprotectant for the following
condition:
800 mM Sodium phosphate monobasic/1200 mM Potassium phosphate dibasic 100
mM Sodium acetate/Aceticacid pH4.5

Thanks
Deepak