Synthetic Gene Circuits

CH2

If we can rebuild a behaviour from parts, we understand it. Our circuits switch, count and remember.

Our workhorse construct

Plasmid Map

pLUM-Sense: doxycycline switches green on, magenta stays on as a reference. Click a segment or choose from the list.

Reporter

2,860–3,577 bp · 718 bp

Superfolder green fluorescent protein. The signal we measure under the microscope.

High-copy origin of replication. Lets E. coli carry hundreds of copies of the plasmid while we clone.
Ampicillin resistance gene. Only bacteria that took up the plasmid survive on ampicillin plates.
Strong promoter that drives the reporter in mammalian cells.
Seven operator sites. Adding doxycycline switches the reporter on or off — the circuit's input.
Superfolder green fluorescent protein. The signal we measure under the microscope.
Self-cleaving peptide, so one transcript makes two separate proteins.
Red fluorescent protein used as an internal reference to correct for cell-to-cell variation.
Polyadenylation signal that ends the transcript cleanly.
Constitutive promoter for the mammalian selection marker.
Puromycin resistance, used to build stable cell lines.

Plasmid map and sequence positions are illustrative for this design sample.

The reporter lights up only when both tumour markers are present. Leak in the “off” rows is what we fight most.

Ongoing2025–2028
A two-input logic gate for tumour-selective expression
An AND gate that expresses a reporter only when two tumour markers are present at once.
Funded by Hanbit Bio-Convergence Program (fictional)
Completed2022–2025
Light-controlled gene expression for tissue patterning
Optogenetic promoters that let us draw stripes of gene expression onto a layer of cells with blue light.
Funded by University Seed Grant (fictional)