Digital experiments for investigating stochastic phenomena in biological systems

Heterogeneity in biological systems necessitates the development of robust single-molecule methods to quantify molecular abundances. Digital methods involve the physical separation of molecular components followed by independent interrogation and robust readout. This approach was used to address problems in a variety of length scales. Microfluidic devices were developed to measure abundances of DNA from single E. coli cells, stochastic heterogeneity of single-molecule polymerase chain reaction was measured, digital cell viability and cell death assays were developed to measure stochastic outcomes of plasmid-encoded toxin-antidote systems, and digital methods were developed to measure plasmid loss rates in a population of growing cells.