Rolling circle amplification revolutionizes diagnosis and genomics of geminiviruses

Better, easier and cheaper than polymerase chain reaction (PCR) or antibody detection, rolling circle amplification (RCA) using the bacteriophage ϕ 29 DNA polymerase allows for a reliable diagnosis of geminiviruses and presumably all viruses with small single-stranded circular DNA genomes. The results show the efficiency of this technique in characterizing viral DNA components of several geminiviruses from experimental and natural host plant sources. The advantages are: (a) that no expensive devices are necessary, (b) simple handling, (c) detection of all infecting circular DNA components without any knowledge of sequence information in a single step, and (d) low costs per reaction. In addition, RCA-amplified viral DNA can be characterized by restriction fragment length polymorphism analysis and directly sequenced up to 900 bases in a single run circumventing cloning and plasmid purification. This shortcut will considerably accelerate genomics of at least gemini-, nano- and circoviruses in the future.