Effects of Chain-Chain Associations on Hybridization in DNA Brushes

Hao Chun Chiang, Rastislav Levicky

Research output: Contribution to journalArticlepeer-review

Abstract

Hybridization of solution nucleic acids to DNA brushes is widely encountered in diagnostic and materials science applications. Typically, brush chain lengths of ten or more nucleotides are used to provide the needed sequence specificity and binding affinity. At these lengths, coincidental occurrence of complementary regions is expected to lead to associations between the nominally single-stranded brush chains due to intra- or interchain base pairing. This report investigates how these associations impact the brushes' hybridization activity toward complementary "target" sequences. Brushes were prepared from 20-mer chains with four-nucleotide-long "adhesive regions" through which neighboring chains could interact. The affinity and position of the adhesive region along the chain backbone were varied. DNA brushes were exposed to complementary solution targets, and the corresponding melting transitions were measured to estimate free energies of the brush-target hybridization. These results revealed that higher affinity adhesive regions more extensively suppressed brush hybridization relative to hybridization in solution. Associations near the middle of the chains were found to be more penalizing than those at the immobilized or the free end of the chains. Provided that the brush chains were close enough to associate, changes in brush density did not exert a significant effect on hybridization thermodynamics within the investigated coverage window. Comparison of the DNA brush results with those from commercial Affymetrix single-nucleotide-polymorphism (SNP) microarrays revealed agreement in the impact of chain associations on hybridization.

Original languageEnglish (US)
Pages (from-to)12603-12610
Number of pages8
JournalLangmuir
Volume32
Issue number48
DOIs
StatePublished - Dec 6 2016

ASJC Scopus subject areas

  • General Materials Science
  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Spectroscopy
  • Electrochemistry

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