For almost half a century, Sanger sequencing has been the conventional method for sequencing DNA. However, its utility for sequencing heterogeneous viral populations is limited because it can only detect mutations that are present in a significant portion of the DNA molecules. Several molecular methods that quantify mutations present at low levels in viral populations were proposed for evaluation of genetic consistency of viral vaccines; however, these methods are only suitable for single site polymorphisms, and cannot be used to screen for unknown mutations.
Part of the book: Steps Forwards in Diagnosing and Controlling Influenza