Hypoosmotic shock causes the delivery of a GPI-anchored protein to the cell surface. (A) Wild-type yeast expressing a Crh2-HaloTag fusion protein (SEY6210 pLG42) were first stained for 30 min at pH4 (standard growth medium) with the membrane-permeable TMR ligand and were then stained for 5 min at pH6.5 with the hydrophilic Alexa488 ligand. The pictures show examples of cells at two different stages of the cell cycle. (B) Cells expressing Nce102-mCherry (cell surface marker) and Crh2-HaloTag (AMY4 pLG42) were grown in the presence of 0.6 M sorbitol, flushed into a microfluidics chamber, and stained with Alexa488 HaloTag ligand for 10 min (first row of pictures). After the switch to hypoosmotic conditions, the cells were stained again with Alexa488 ligand for 5 min (second row of pictures). (C) Quantification of the experiments shown in B (AMY4 pLG42, MTY52 pLG42).