Synthesis of oligodeoxyribonucleotides by solid phase phosphotriester method on a reduced scale; preparation of oligonucleotides for improved promoter sequence.

A small reaction vessel, composed of a balled sintered glass filter and a test tube with a stopcock, was designed for the solid phase phosphotriester synthesis of oligodeoxyribonucleotide. Operation of small scale synthesis (nucleoside on resin: 3-6 mumol, activated diester of dimer: 20-30 mumol) was performed under the atmosphere of argon. The yield of each coupling reaction was 60-100%. Twelve short oligonucleotides (6-16mer) were obtained in 19-78% overall yield by this method. These oligomers were prepared as a part of the control region of gene to increase the translation efficiency.