Single cell RNA expression of TS transcripts. (a) Antisense probe; (b) sense probe; (c) both sense and antisense probes bound to the fixed and reverse transcribed TS RNA in HeLa cells. Probes were designed to cover exon boundaries and a part of the overlap region in a strand specific manner. (d) Signals from the actin probe show that the method was working optimally. All the probes were intron spanning to avoid background signal from contaminating DNA.