Use of Cell-ID to quantify fluorescence translocation. (a) Cells containing YFP-Ste5 are shown just
before (left) and then 10 seconds after (right) pheromone stimulation. The Ste5 scaffold proteins
translocate to the membrane as indicated by enhanced fluorescence at the boundary and the depleted
fluorescence in the cytoplasm. (b) Schematic showing how Cell-ID begins to analyze such data. A bright-
field image is sown for two sample cells before (upper left) and after (upper right) identification and
annotation with Cell-ID. Cell-ID then calculates the membrane pixels and annuli of successively smaller
radius (bottom left). It then uses these to analyze interior and boundary regions of the fluorescence
image (bottom right, shown only with membrane region drawn).