Filter binding assay

Introduction

• Advantage: easy to perform
• Disadvantage: cannot distinguish different types of complexes as EMSA and footprint

Rationale

• Double stranded DNA can pass through the nitrocellulose (NC) paper, but the DNA-protein complex cannot pass through the NC filter. By quantifying the complex retained on the filter, user can determine the binding constant of this interaction.

Methods

• Lable DNA
• Mix DNA and protein to form complex
• Pass the mixture through an NC filter
• Quantify the amount of DNA (in the complex) on the filter