Preparation Of High-Density Peptide Nucleic Acid Microarray Via Photodeprotection Chemistry Using Virtual Masks

Peptide nucleic acid (PNA) is a DNA mimic that has a polyamide backbone. The employment of PNA as probes in gene microarray instead of DNA could circumvent many problems encountered in the usage of gene microarray in molecular biology and biomedical application, e.g. the dilemma of affinity and specificity. In this paper, PNA monomers were synthesized, and high-density PNA microarray was prepared. Major work includes:This paper introduced a virtual mask photolithographic system, and discussed a focal plane adjustment method based on fluorescent reagent staining.By analyzing the strategies of synthesizing a PNA microarray, this paper uses the concept of supersequence to reduce synthesis cycles; by analyzing negative effect of the diffraction of DMD, a "stretching" model was introduced to reduce insertion risk of the probe. Meanwhile, a software was developed to produce virtual mask images needed for the synthesis of PNA microarray.In this paper, four PNA monomers were synthesized. These monomers have their backbone protected by light labile protective grope2-(2-nitrophenyl) propyloxy carbonyl (NPPOC), and their exocyclic amino groups protected by amide carbonyl groups. Structures of the monomers were verified by NMR and Mass Spectrometry.PNA microarray was synthesized through photodeprotection chemistry using virtual masks that has the density of more than10000probes per square centimeters. The hybridization result indicates that PNA microarray can screen single and multiple base mismatches correctly, proved the feasibility of preparing high-density peptide nucleic acid microarray via photodeprotection chemistry using virtual masks. This work serves to lay the foundation of PNA microarray application.