Pushing into a new chapter of technologically advanced biological sensors, scientists from the University of California San Diego and colleagues in Australia have engineered bacteria that can detect the presence of tumor DNA in a live organism. Their innovation, which detected cancer in the colons of mice, could pave the way to new biosensors capable of identifying various infections, cancers and other diseases. The advancement was published August 9, 2023, in the journal Science. Bacteria previously have been designed to carry out various diagnostic and therapeutic functions, but lacked the ability to identify specific DNA sequences and mutations outside of cells. The new “Cellular Assay for Targeted CRISPR-Discriminated Horizontal Gene Transfer,” or “CATCH,” was designed to do just that.