N2-Phenoxyacetyl-guanosine is a protected guanosine nucleoside derivative essential for solid-phase RNA oligonucleotide synthesis. The phenoxyacetyl (PAC) protecting group on the N2 position of guanine enables selective protection during coupling steps and rapid deprotection under mild basic conditions, ensuring high-yield production of RNA oligos. It is widely used in molecular biology and biochemistry for preparing RNA sequences to study structure, function, interactions, gene expression, and for developing therapeutic oligonucleotides like siRNA and antisense agents targeting RNA-related diseases.