Hi Yuvraj, Here are some thoughts in addition to what's been suggested already:
1. A good recent reference is here: http://journals.iucr.org/f/issues/2015/06/00/en5564/index.html 2. The image you sent suggests cubic ice, indicating a higher glycerol concentration (maybe 35 or 40%) is needed. Also consider stepwise equilibrations. 3. Glycerol and ethylene glycol can increase protein solubility, so if the crystal cannot tolerate the higher glycerol concentration try some other classes of cryoprotective agents (e.g. sugars, methylamines (i.e. TMAO), alcohols, mixtures...see the above reference) Best, Doug
