The pSP64 Poly(A) Vector is a standard cloning vector that can be used for in vitro transcription and to generate poly(A)+ transcripts in vitro. The vector has a stretch of 30 dA:dT residues inserted between the SacI and EcoRI sites. Therefore, when foreign DNA is cloned into any polylinker site other than EcoRI (HindIII, PstI, SalI, AccI, HincII, XbaI, BamHI, AvaI, SmaI or SacI), linearization of the recombinant plasmid with EcoRI allows the use of SP6 RNA polymerase in vitro to prepare RNA copies of the inserted sequences that contain a synthetic 3´ “poly(A)” tail of 30 residues. Poly(A) tails can stabilize RNAs and lead to greater yields for in vitro translation reactions.