a) providing at least one first round single stranded cDNA molecule having a 5′ end and a 3′ end;

b) attaching an oligodeoxynucleotide tail onto the 3′ end of said first round cDNA molecule;

c) annealing to said oligodeoxynucleotide tail a single stranded promoter template comprising a first RNA polymerase recognition sequence and at least a second different RNA polymerase recognition sequence 3′ to said first recognition sequence, wherein said single stranded promoter template is not extendable with DNA polymerase;

d) extending said oligodeoxynucleotide tail such that said single stranded promoter template is converted into a first RNA polymerase promoter and at least a second RNA polymerase promoter 3′ to said first promoter;

e) initiating a first round of RNA transcription using an RNA polymerase which recognizes said first RNA polymerase promoter to produce at least one first round sRNA molecule;

f) synthesizing at least one second round single stranded cDNA molecule from said first round sRNA molecule, said second round single stranded cDNA molecule having 5′ and 3′ ends;

g) degrading said first round sRNA molecule;

h) annealing a single stranded promoter oligonucleotide complementary to said second different RNA polymerase recognition sequence such that a second RNA polymerase promoter is formed; and

i) initiating a second round of RNA transcription using an RNA polymerase which recognizes said second RNA polymerase promoter to produce at least one second round sRNA molecule,