Representative results of analysis of microsatellite instability in single cell clones of KCL22. Single cell clones of KCL22 exhibit microsatellite instability at D2S123 (A) and D18S58 (B). Each lane represents an independent subclone. DNA samples were prepared from single cell clones isolated by limiting dilution, and polymorphic microsatellite sequences were amplified by PCR and analyzed in denaturing sequencing gels. Subclones of KCL22 display different patterns of laddering at both polymorphic microsatellites.