The stability of immobilized mRNA against ribonucleases was investigated in a cell-free protein synthesis system. The plasmid-encoding protein A with the 20-mer poly(A) tail under the control of T7 promoter was constructed, and the corresponding mRNA was synthesized by T7 RNA polymerase reaction. The resulting mRNA was immobilized on oligo(dT)-immobilized latex beads by hybridization utilizing the poly(A) tail of mRNA at the 3＇-terminus. The mRNA was stabilized against three types of nucleases (3＇-OH exonuclease, 5＇-OH exonuclease, and endonuclease) by immobilization. Translation of immobilized mRNA with a continuous-flow cell-free protein-synthesizing system from Saccharomyces cerevisiae was ascertained. Reusability of the immobilized mRNA as genetic information was also examined.