RcGTA, a small phage-like particle produced by Rhodobacter capsulatus, was initially identified in culture filtrates as a DNase-resistant form of DNA transfer between R. capsulatus cells. This gene transfer assay has been used to identify RcGTA-producing strains and to help determine the roles of genes thought to be responsible for RcGTA production.
Hynes, A. P. and Lang, A. S. (2013). Rhodobacter capsulatus Gene Transfer Agent (RcGTA) Activity Bioassays. Bio-protocol 3(2): e317. DOI: 10.21769/BioProtoc.317.