Comparison of enzymatically polyadenylated RNA with tailed IVT RNA transcribed from a template encoding the poly(A) tract. (A) Template IVT RNA before polyadenylation (lane 1) compared with IVT RNA products obtained in independent polyadenylation reactions with increasing concentrations of poly(A) polymerase (lanes 2-5), resulting in increasing sizes of poly(A) tail lengths. (B) IVT RNA with an enzymatically attached poly(A) tail was purified and analyzed. The electropherograms (left) and gel images (right) disclose a mixture of RNA species differing in length. (C) Electropherograms (left) and gel images (right) of purified IVT RNA obtained from a plasmid template encoding the poly(A) tail show a well-defined homogenous RNA species.