Fig. 3. Quantitation of substratum choice assay. The response rate expressed as the percentage of axons turning or stopping at the border of EphB-ECD or Fc control containing substratum. ‘None’ shows the results of quantitation of a virtual border drawn on a uniform laminin substratum. Results from dorsal and ventral retinal explants were quantified separately. (A) Response rate (percentage either stopping or turning at border) from pooling all individual axon encounters of a given condition. (B) Mean percentage of axons stopping or turning at the border for each explant. Error bars show s.e.m.