Abstract: A method for identifying an interaction between a pathogen and a biological agent includes providing a platform for supporting cell growth, seeding different interaction sites on the platform with different biological agents, perfusing the platform with a fluid that carries substances for promoting growth and maintenance of the cells, exposing all of the interaction sites to a solution containing viruses, and detecting evidence indicative of the interaction, the evidence comprising evidence indicative of a change in structure or composition of a medium at the interaction site. The biological agent includes cells alone or cells with another substance.

Abstract: Described herein are genetically engineered template-independent DNA polymerases, specifically terminal deoxynucleotidyl transferases, and methods of using these polymerases to control DNA synthesis by adding a single nucleotide (mononucleotide) at a time to the 3? end of a growing single-stranded DNA polynucleotide.