E. coli Poly (A) Polymerase does not depend on the presence of template, and can catalyze the sequential incorporation of ATP in the form of AMP into the 3´ terminal of RNA, i.e., the addition of polyA tail to the 3´ terminal of RNA. Poly (A) polymerase has A high tail adding efficiency and can add 20 to 200 A bases to the 3´ terminal of RNA. Polyadenylation improves the stability of RNA in cells and enhances the expression efficiency of RNA after transfection or microinjection. Poly(A) tails can be used as primer binding sites for first-strand cDNA synthesis in some applications and can be used for end-labeling or quantification of miRNA. The original enzymes of T7 RNA Transcription Enzyme Mix produced in E. coli. Our manufacturing processes are strictly controlled to ensure the end products free from host protein or nucleic acid contaminations and other impurities following the Pharmaceutical Manufacturing Guidelines. We guarantee the manufacturing and quality control comply with GMP regulation for tracking each and every step of the manufacturing process, including raw material sourcing.