Single-Molecule Imaging of DNAs with Sticky Ends at Water/Fused Silica Interface

Thesis/Dissertation · Sat Jan 01 04:00:00 EST 2005

DOI:https://doi.org/10.2172/861626· OSTI ID:861626

Isailovic, Slavica ^[1]

---

1. Iowa State Univ., Ames, IA (United States)

Total internal reflection fluorescence microscopy (TIRFM) was used to study intermolecular interactions of DNAs with unpaired (sticky) ends of different lengths at water/fused silica interface at the single-molecule level. Evanescent field residence time, linear velocity and adsorption/desorption frequency were measured in a microchannel for individual DNA molecules from T7, Lambda, and PSP3 phages at various pH values. The longest residence times and the highest adsorption/desorption frequencies at the constant flow at pH 5.5 were found for PSP3 DNA, followed by lower values for Lambda DNA, and the lowest values for T7 DNA. Since T7, Lambda, and PSP3 DNA molecules contain none, twelve and nineteen unpaired bases, respectively, it was concluded that the affinity of DNAs for the surface increases with the length of the sticky ends. This confirms that hydrophobic and hydrogen-bonding interactions between sticky ends and fused-silica surface are driving forces for DNA adsorption at the fused-silica surface. Described single-molecule methodology and results therein can be valuable for investigation of interactions in liquid chromatography, as well as for design of DNA hybridization sensors and drug delivery systems.

• Research Organization: Ames Lab., Ames, IA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 861626
• Report Number(s): IS--T 2278
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
59 BASIC BIOLOGICAL SCIENCES
ADSORPTION
AFFINITY
CHROMATOGRAPHY
DESIGN
DNA
DNA HYBRIDIZATION
FLUORESCENCE
MICROSCOPY
PH VALUE
REFLECTION
SILICA
VELOCITY