Most eukaryotic mRNAs require a 7-methyl guanosine (m7G) cap structure at the 5' end and a Poly(A) tail at the 3 end to be efficiently translated. By using a DNA template encoding a poly(A) tail, the HiScribe T7 ARCA mRNA Kit can be used to synthesize capped and tailed mRNAs. The cap structure is added to the mRNA by co-transcriptional incorporation of Anti-Reverse Cap Analog (ARCA) using T7 RNA Polymerase. Poly(A) tail is incorporated during the transcription reaction. The kit also includes DNase I and LiCl for DNA template removal and quick mRNA purification. Additionally, the kit is capable of partial incorporation of modified UTP and CTP (up to 50% each) without affecting the mRNA yield significantly. By using a DNA template encoding a poly(A) tail, capped and tailed modified mRNA can be synthesized in a single reaction in 30 minutes. mRNAs synthesized with the kit can be used for cell transfection, microinjection, in vitro translation and RNA vaccines.