Assessment of mouse sera.

A Dot blot of CHO hS1P1-GFP cell membranes (1.6 μg of sample was spotted onto the PVDF (polyvinylidene fluoride) membrane and revealed with 1:1,000 v/v diluted sera). B Pure hS1P1-cmyc from Pichia yeast cells (1 μg of sample per lane) was detected by Western blot using sera from five different immunized mice (1:5,000 v/v). C hS1P1 was detected in membrane fractions from CHO expressing hS1P1-GFP cells (20 μg of sample per lane) using sera from five different immunized mice (1:5,000 v/v).