Figure 2

Illustration of inhibition measurement at the periphery. (a) The macrocolony is divided vertically into unexposed (left) and exposed (right) halves. The CHX spot is horizontal to the right of the macrocolony in each image. Each macrocolony half is separately mirrored and the resulting contour fitted to an ellipse. Red background in leftmost image reflects the Euclidean distance of each pixel from the CHX source. Outer contours are shown in bright red. (b) Colony periphery deformation analysis. At each distance from CHX source (control and 1/1.5/2 cm) the ratio between horizontal (left) and vertical (right) radii between the unexposed and exposed halves is shown.