Given the task definition and input, reply with output. In this task, you're given a paragraph from the research paper and your task is to generate a suitable title for the research paper based on the given paper. Under 100 words is a good title length.

For epidemic control, rapid identification and characterization of the responsible unknown agent are crucial. To address this critical question, a method was developed for virus discovery based on a flexible nested-PCR subtraction hybridization. As a positive control, we used hepatitis C virus as a hypothetical unrecognized virus and "discover" it in the sample. Using template-switching universal long-PCR to produce large quantities of cDNA, our nested-PCR-based subtractive hybridization coupled with a single-strand deletion technology removed most of the common cDNA. Following subtraction hybridization, a cDNA library was constructed and displayed by differential reverse dot blot hybridization. This new genomic subtraction hybridization method will be ideally suited to identify rapidly any previously unrecognized viral agent. Published by Elsevier B.V.
Rapid approach to identify an unrecognized viral agent