tokens: One hundred percent of the colonies carrying SK - N - BE ( 2 ) p53 , which is homozygous for the C135F mutation , turned red with the standard or 5 ' split assay , whereas 94 % of the colonies turned white with the 3 ' split assay since the missense mutation does not extend to the C ' - terminus of the gene ( Table 2 and Figure 4B , dish c ) .