The first step in their experiments was to create circularly permuted GFP which was done by inserting various amino acids on the N-terminus of a family of second messenger molecules. Products of this insertion included a circular GFP and a circularly permuted clover shaped GFP. Two other GFP molecules were obtained by linking the C and N-termini of cpsfGFP-OPT using peptides. Once the GFP molecules were produced the authors proceeded to produce their sensor, called ASAP1, by using a voltage sensitive domain (VSD) from a phosphatase (VSP) from a chicken (Gallus …show more content…
Comparison of ASAP1 and ArcLight show that ASAP1 continuously provides sharper and more defined peaks in response to these voltage changes. ASAP1 produced higher F/F, which corresponds to fluorescence change, than ArcLight; in some cases this difference was over 3% with higher applied voltages. Figure 4 shows data collected from hippocampal cells transfected with both ASAP1 and ArcLight which were subjected to subthreshold potentials. ASAP1 provided the highest fluorescence response while in some cases ArcLight did not even detect the action potential. This specific outcome provides a strong case for the engineering and specific placement of