A suite of spin-state-selective excitation (S3E) NMR experiments for the measurements of small one-bond (13C-13C, 15N-13C) and two-bond (1H-13C, 1H-15N) coupling constants in 13C,15N labeled purine and pyrimidine bases is presented. The incorporation of band-selective shaped pulses, elimination of the cross talk between alpha and beta sub-spectra, and accuracy and precision of the proposed approach are discussed. Merits of using S3E rather than alpha/beta-half-filter are demonstrated using results obtained on isotopically labeled DNA oligonucleotides.