M. Beier et al., Synthesis of photolabile 5 '-O-phosphoramidites for the photolithographic production of microarrays of inversely oriented oligonucleotides, HELV CHIM A, 84(7), 2001, pp. 2089-2095
The photolabile 3 ' -O-{[2-(2-nitrophenyl)propoxy]carbonyl}-protected 5 ' -
phosphoramidites (16-18) were synthesized (see Scheme) for an alternative m
ode of light-directed production of oligonucleotide arrays. Because of the
characteristics of these monomeric building blocks, photolithographic in si
tu DNA synthesis occurred in 5 ' --> 3 ' direction, in agreement with the o
rientation of enzymatic synthesis. Synthesis yields were as good as those o
f conventional reactions. The resulting oligonucleotides are attached to th
e: surface via their 5 ' -termini, while the 3 ' -hydroxy groups are availa
ble as substrates for enzymatic reactions such as primer extension upon hyb
ridization of a DNA template (see Fig. 2). The production of such oligonucl
eotide chips adds new procedural avenues to the growing number of applicati
ons of DNA microarrays.