Photolithographic synthesis

Beier M., Hoheisel J.D., Production by quantitative photolithographic synthesis of individually quality checked DNA microarrays, Nucl Acid Res. 2000 28 el 1. 

DNA arrays are fabricated by immobilizing the complementary DNA (cDNA) onto a solid substrate such as silicon, nylon or glass. This can be achieved by robotic printing of polymerase chain reaction (PCR) products (also known as direct-deposition approach), photolithographical synthesis of complementary oligonucleotides or piezoelectric inkjet printing of PCR products (also known as indirect-deposition approach). 

FIGURE 11.2 Photolithographic synthesis of oligonucleotide probe arrays. 

Figure 2.2 Photolithographic-based DNA synthesis. (From Pease, A.C. etal., Proc. Natl. Acad. Sci. USA, 91, 5022-5026, 1994. With permission.)...

Steiner et al. designed photoremovable protecting group 103 for photolithographic in situ DNA-chip synthesis (Scheme 49). " These protecting groups have a... 

Oligonucleotide and peptide microarrays can be prepared in situ with light-directed synthesis on a glass surface in conjunction with either a photolithographic method or using a micromirror device (2,11-15). However, these methods are not useful for most organic synthesis. Furthermore, such approaches require equipment that is not readily available. Spot synthesis on cellulose membrane is another in situ synthesis method, but the resulting microarrays are low density (16). 

Fig. 1. Light-directed synthesis of polynucleotide probe arrays. Exposure to light through a photolithographic mask is used to remove protecting groups from surface sites in pre-defined regions of a functionalized glass substrate. A solution of an activated polynucleotide building block is then applied, which reacts specifically in the exposed regions of the substrate. Repeated cycles of illumination-deprotection and monomer coupling are used to construct a two-dimensional array of probe sequences...

Pirrung MC, Fallon L, McGall G (1998) Proofing of photolithographic DNA synthesis with 3, 5 -dimethoxybenzoinyloxycarbonyl-protected deoxynucleoside phospho-ramidites. J Org Chem 63 241-246... 

The second platform for DNA microarray fabrication involves controlled in situ synthesis of oligonucleotides (on-chip). This technology, implemented by Affymetrix in the manufacture of GeneChips, uses photolithographic... 

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