A Novel Method for Pegylation of Quartz Slides

Open Access
Cotton, Victor
Area of Honors:
Bachelor of Science
Document Type:
Thesis Supervisors:
  • Tae Hee Lee, Thesis Supervisor
  • Raymond L Funk, Honors Advisor
  • DNA
  • Histone
  • H1
  • Nucleosome
  • PEG
Binding-based assays are valuable tools in studying proteins and nucleic acids, and are constantly used to determine both the structure and function of these molecules. An integral part of these assays is the medium on which the molecules are analyzed. The medium on which the assay is conducted is often a glass surface. The surface must be manipulated such that certain molecules bind the surface and others do not, allowing precise study of specific molecules that bind the surface. Such binding specificity is imperative for obtaining accurate results from assays. However, difficulty arises in creating such a surface that binds the desired compounds and sheds all others. Here, the problem addressed is creating a quick and efficient method to functionalize a glass microscope slide for DNA and histone H1 assays. A common method used for such assays is functionalization with polyethylene glycol (PEG). While this method is excellent for DNA assays, the histone H1 is highly positively charged and readily binds this surface, as the typical PEG surface concentration is often not sufficient to mask the negative charge on a quartz microscope slide completely. A novel method to increase the surface concentration of PEG conjugated to a microscope slide surface is tested here with the intent to minimize the affinity of H1 for the surface. Making this surface involves connecting biotin to the surface of a quartz slide, then using the biotin-binding protein StreptAvidin to tether biotinylated PEG to the biotinylated surface. This surface is shown to have a lesser affinity for H1 than a standard PEG surface, indicating a high potential for success in future experiments with other DNA binding proteins. This surface could allow for more accurate characterization of the properties of histone H1.