Expanded DNA alphabet in amplification
and hybridization based sensing
Multiplexed PCR sensing
Advantage
• Cheaper to run
• Simpler/faster assay setup
Challenges
• Lowered sensitivity
• Lowered accuracy
Some sources of multiplex challenges (and
general) are optimizing interactions between
various primers, probes, and sample
Expanded genetic code:
artificially expanded genetic
information systems (AEGISs)
• Extra bases Z and P, evolved
DNA polymerase will replicate
them
• In lieu of dC, the polymerase
used can incorporate the
deprotonated form of dZ
• Enables PCR reaction to
generate A-T-G-Z amplified
fragments
– Enhances specificity of
amplification
Detection with Z:P pair probe
self-avoiding molecular recognition systems (SAMRSs)
Paper based DNA prep
• Ammonium (-NH3+) based paper was optimized:
capillary mosquito saliva extract on paper
wash, then elute with ammonia
 spin column desalt
 RT-PCR, then ATGZ PCR, then hybridization to
fluorescent probe
Expanded alphabet part (2):
• Featured in Science in
Feb 2019
• Works with an evolved
RNA polymerase
• Doesn’t work with DNA
polymerase
• Future applications
could include SAMRSs
PCR sensing, and
aptamer evolution with
greater chemical
diversity