Abstract: Universal solid support oligonucleotide synthesis reagents, oligonucleotide synthesis processes, and reagents for cleaving oligonucleotides from solid supports are disclosed. Oligonucleotide synthesis reagents have the following general formula:SS--R.sup.6 --O--R.sup.3 Iwherein SS is a solid support; R.sup.6 is ##STR1## where R.sup.5 is hydrogen or alkyl and R.sup.4 is a phosphate protecting group; and R.sup.3 is a ring moiety having vicinal groups --XR.sup.1 and --YR.sup.2 wherein each of X and Y is independently selected from the group consisting of O, S and NH and one of R.sup.1 and R.sup.2 is a blocking moiety and the other is hydrogen or a hydroxy protecting group. Oligonucleotide cleaving reagents include methylamine and/or ammonium hydroxide and trimethylamine.

Abstract: Discloses DNA isolation and purification methods which involve novel washing steps. The disclosed methods provide a means for isolating and purifying DNA from a homogeneous mixture of DNA of other cellular contaminants by treating silica with the homogeneous mixture containing DNA in the presence of a chaotropic salt solution and then washing and separating the washed and treated silica in successive wash steps with aqueous alcohol wash solutions. A first wash step involves washing the treated silica with a first wash solution of at least 95 wt % alcohol in water. A second wash step similarly involves washing the treated and washed silica with second wash solution of less than 95 wt % alcohol in water.