Table 1 Primers for the strand-specific PCR and PCR conditions

First strand synthesis of DHFR transcribed strand

DHFR_UP-TSP1

5'-GAGTCGAGTCGACATCG AGCCACTGTGCCCGGTCAGAC-3'

94°C 15 s, 62°C 15 s, 72°C 60 s for 1 cycle

First strand synthesis of DHFR non-transcribed strand

DHFR_UP-NTSP1

5'-GAGTCGAGTCGACATCG GGATGTGCCCTGGTGACTGGA-3'

94°C 15 s, 62°C 15 s, 72°C 60 s for 1 cycle

Amplification of DHFR transcribed strand

DHFR_TSP2

5'-GGATGTGCCCTGGTGACTGGA-3'

94°C 15 s, 62°C 15 s, 72°C 40 s for 25 cycles

UP

5'-GAGTCGAGTCGACATCG-3'

Amplification of DHFR no-transcribed strand

DHFR_NTSP2

5'-AGCCACTGTGCCCGGTCAGAC-3'

94°C 15 s, 62°C 15 s, 72°C 40 s for 25 cycles.

UP

5'-GAGTCGAGTCGACATCG-3'

First strand synthesis of c-myc transcribed strand

c-myc_UP-TSP1

5'-GAGTCGAGTCGACATCG AACTTTGTGCCTTGGATTT-3'

94°C 15 s, 58°C 15 s, 72°C 60 s for 1 cycle

Amplification of c-myc transcribed strand

c-myc_TSP2

5'-TACTGGAGCTGATGCTGAGC-3'

94°C 15 s, 58°C 15 s, 72°C 40 s for 25 cycles

UP

5'-GAGTCGAGTCGACATCG-3'

Amplification of β-actin

β-actin P1

5'-GCCAGGTCCAGACGCAGGAT-3'

94°C 15 s, 62°C 15 s, 72°C 10 s for 22 cycles

β-actin P2

5'-TGCTATCCCTGTACGCCTCTG-3'