Date of Completion
Ping Yan; James Cole
Structural Biology and Biophysics
Second Honors Major
Molecular and Cell Biology
Voltage sensitive dyes (VSDs) are voltage reporters which are used to measure electrical activity in cells . Tethered VSDs are a new class of VSD which consist of a flu- orophore and quencher component attached via hydrocarbon chain that is approximately the same length of a cell membrane. These dyes demonstrate potential to overcome the issues of poor fluorescence change in response to a changing electrical potential (low sensitivity) and insufficient speed that current VSDs exhibit while measuring electrical activity of a cellular membrane. While tethered dyes have been able to demonstrate high levels of sensitivity in an in-vitro system , further optimization of fluorophore-quencher combinations will allow for the measurement of electrical activity in the near-IR (NIR) region with enhanced sensitivity, resulting in high quality recordings with significantly less equipment and labor required. Three different fluorescent molecules have been identified as possible tethered VSD components, these being a modified Fluorescein based molecule, a DiSBAC(5) [Bis-(1,3-dibutylthiobarbituric acid) pentamethine oxonol] molecule, and a modified Cy-5 molecule. In-vitro measurements of an induced changing electrical field have resulted in sensitivity measurements of up to 11%/100 mV fluorescence change for a DiSBAC(5) molecule in a two-component system with a previ- ously synthesized di-4-ANEPPS molecule. Modifications to structure, fluorophore/quencher combinations, as well as tethering the previously mentioned molecules are likely to strengthen these sensitivity measurements further making their use for an in-vivo system more feasible.
Fairchild, Daniel, "Synthesis and In-Vitro Voltage Sensitivity Testing of Two-Component Voltage Sensitive Dyes" (2021). Honors Scholar Theses. 789.