IN earlier publications^1,2 we described the preparation of soluble glucose-6-phosphatase (G6Pase) from microsomes of bovine liver. We always found that a combined treatment of the microsomes with sodium deoxycholate and digitonin leads to a reproducible solubilization of this enzyme. However, it was noted that G6Pase is very sensitive towards sodium deoxycholate and under the latter's influence activity is markedly diminished.