Electrophoretic Mobility Shift Assay (EMSA) of Resected Tissue Extracts with Purine Triplex DNA. 33P-labeled purine-motif triplex DNA (1 nM) was complexed with 5 μg total protein from normal cytoplasmic (N cy), normal nuclear (N nu), tumor cytoplasmic (T cy) or tumor nuclear (T nu) extracts of tissues obtained from eight selected colorectal cancer patients. 1.25 μg HeLa cytoplasmic and nuclear extracts were used as positive (+) controls. The major EMSA band was H3, indicated with an arrow. Normalized EMSA H3 values are listed below the corresponding samples. The purine-motif triplex probe alone is shown in lane 1.