NimbleGen's Maskless Array Synthesis ..

Photogenerated acid (PGA) was used as the acid to remove the protection group from amino acids or peptide oligomers. Comparative study of the deprotection using a PGA, trisarylsulfonium antimonyhexafluoride (SSb), and trifluoroacetic acid (TFA) was performed on glass microscope slides. The results showed that PGA can replace TFA in the deprotection step of oligopeptide synthesis with comparable efficiencies. Acids needed for the deprotection step were generated in situ by light activiation of the precursor molecule on the microwell substrate. A maskless laser light illumination system was used to activate the precursor. The accuracy of the amino acid sequence of the synthesized oligopeptide and the location of the synthesis was illustrated by the specific recognition binding of two different models: lead(II) ion-peptide biosensor for lead(II) and human protein p53 (residue 20-25)-mouse MAb DO1. After parallel synthesis of the target peptide models and their analogues based on the predetermined pattern, specific binding treatment, and fluorescence labeling, the fluorescence emission images of the oligopeptide microarray showed fluorescence intensity as a result of specific binding at the correct locations of the array. The stepwise synthesis efficiencies of pentapeptide synthesis on the microwell substrate range are ∼96-100% and do not decrease with respect to the chain length of the peptide.

for the Maskless Array Synthesis ..

using maskless array synthesis technology.

Nimblegen Maskless Array Synthesis

A schematic of the optical system of the maskless array synthesizer is shown in Figure . Loss of optical contrast is mainly due to two factors, flare (scattering) and diffraction. Global flare originates from dust and imperfections in the optical system and results in a spatially homogenous background exposure that is proportional to the total number of ON mirrors as shown in Figure . In this experiment, a calibrated intensity meter is placed at the focal plane (replacing the synthesis cell), with a mask blocking all but a small central area of the light-sensitive surface as shown with the label "UV-detector" in Figure . With all the mirrors that direct light directly to the detector turned OFF, the measured signal is primarily from global flare irradiance originating from ON mirrors that do not image into the detector. At the high end of number of ON mirrors, 64%, we were able to measure a global flare irradiance of 0.1% of direct irradiance using a calibrated intensity meter. This corresponds to a global flare of less than 0.04% of synthesis irradiance for a 1:1 layout (all mirrors used) high density microarray, where an average of 25% of the mirrors are used in each deprotection step. This corresponds to a contrast ratio of better than 1/2500 (global flare only).

Looking for online definition of array synthesis in the Medical ..

Maskless array synthesis relies on the effective removal of the 5'-NPPOC hydroxyl protecting group of oligonucleotides prior to coupling a new base. The rate of photochemical removal of this group is directly proportional to light intensity and the number of remaining protecting groups:

KW - Maskless Array Synthesis
Maskless array synthesis

Life Sciences Business Intelligence for European countries ..

Light-directed in situ synthesis of DNA microarrays using computer-controlled projection from a digital micromirror device--maskless array synthesis (MAS)--has proved to be successful at both commercial and laboratory scales. The chemical synthetic cycle in MAS is quite similar to that of conventional solid-phase synthesis of oligonucleotides, but the complexity of microarrays and unique synthesis kinetics on the glass substrate require a careful tuning of parameters and unique modifications to the synthesis cycle to obtain optimal deprotection and phosphoramidite coupling. In addition, unintended deprotection due to scattering and diffraction introduce insertion errors that contribute significantly to the overall error rate.

07/06/2015 · Here we describe a maskless array synthesizer ..

Introduction to DNA microarray technology

We report an approach to the in situ synthesis of oligonucleotide arrays on surfaces coated with crosslinked polymer multilayers. Our approach makes use of methods for the "reactive" layer-by-layer assembly of thin, amine-reactive multilayers using branched polyethyleneimine (PEI) and the azlactone-functionalized polymer poly(2-vinyl-4,4′-dimethylazlactone) (PVDMA). Postfabrication treatment of film-coated glass substrates with d-glucamine or 4-amino-1-butanol yielded hydroxyl-functionalized films suitable for the Maskless Array Synthesis (MAS) of oligonucleotide arrays. Glucamine-functionalized films yielded arrays of oligonucleotides with fluorescence intensities and signal-to-noise ratios (after hybridization with fluorescently labeled complementary strands) comparable to those of arrays fabricated on conventional silanized glass substrates. These arrays could be exposed to multiple hybridization/dehybridization cycles with only moderate loss of hybridization density. The versatility of the layer-by-layer approach also permitted synthesis directly on thin sheets of film-coated poly(ethylene terephthalate) (PET) to yield flexible oligonucleotide arrays that could be readily manipulated (e.g., bent) and cut into smaller arrays. To our knowledge, this work presents the first use of polymer multilayers as a substrate for the multistep synthesis of complex molecules. Our results demonstrate that these films are robust and able to withstand the ∼450 individual chemical processing steps associated with MAS (as well as manipulations required to hybridize, image, and dehybridize the arrays) without large-scale cracking, peeling, or delamination of the thin films. The combination of layer-by-layer assembly and MAS provides a means of fabricating functional oligonucleotide arrays on a range of different materials and substrates. This approach may also prove useful for the fabrication of supports for the solid-phase synthesis and screening of other macromolecular or small-molecule agents.

26/02/2013 · The arrays were manufactured by maskless array synthesis ..

error and yield in light-directed maskless synthesis of ..

BSA: Bovine serum albumin; Cap A: Tertbutylphenoxyacetyl acetic anhydride in tetrahydrofuran (1:1); Cap B: 10% N-methylimidazole in tetrahydrofuran/pyridine (8:1); DCI: 4,5-dicyanoimidazole; DMD: Digital micromirror device; DMT: Dimethoxytrityl; NPPOC: 2-(2-nitrophenyl)propyloxycarbonyl; MAS: Maskless array synthesis; MES 2-(N-morpholino)ethanesulfonic acid; SSC: Saline-sodium citrate; Tac2O: Tertbutylphenoxyacetyl acetic anhydride; XGA: Extended graphics array.