Dose-response for ablation of c-myc mRNA and inhibition of proliferation of KYO1 cells by a chimeric methylphosphonodiester / phosphodiester antisense oligodeoxynucleotide. Cells were loaded by streptolysin permeabilization from the indicated external concentrations of oligodeoxynucleotide 5'F-MD757AS (Table 1). (A) Relative levels of c-myc and GAPDH mRNA at 4 h. Mean and standard deviation of 3 replicates. (B) Increase in cell number / ml over 20 h from an initial cell density of 5 × 105 / ml. Mean and standard deviation of 3 replicates.