crazyboy - 17-11-2014 at 13:54
Hey it's been a while. I'm in a instrumentation class where we have been tasked with designing a novel assay or DNA sequencing technique. I had the
idea of designing a technique where the addition of base could be detected by a change in color of a substrate. The idea would be that a fragment to
be sequenced would be sequentially exposed to one nucleotide at a time, if it is integrated the pyrophosphate would be converted to ATP as in
pyrosequencing however the ATP would activate an enzyme which induces a reversible color change.
What I'm having trouble with is coming up with a small molecule or protein which would be suitable for this. Ideally the molecule will be colorless or
have a certain absorbance in one state and then will be converted to a colored state or a state which it has a different spectral absorbance. Also
ideally the substance would be regenerated to its original state easily such as by light or heat.
I thought maybe beta carotene or another colored substance with a conjugated pi system could be disrupted by a reductase but I'm not sure how that
would be reversed. Alternatively changing the oxidation state of a complexed metal ion.
Alternatively if the molecule could was highly sensitive to pH changes that could work as H+ is liberated by nucleotide integration.
I suppose if all the enzymes were immobilized the signalling chemical could be replaced after each addition but that might introduce new problems (or
not)
What do you guys think?
Chemosynthesis - 17-11-2014 at 14:32
Why post this in Organic Chemistry?
Cyclic voltammetry of a transition metal complex that changes color based on pH (similar to PMID 16156624) ala ion torrent sequencing.
crazyboy - 17-11-2014 at 17:14
You're right, probably should be moved to general. It's a hard thing to conceive, if it was simple it's already been done and if it's brilliant I
can't figure it out.
[Edited on 18-11-2014 by crazyboy]