PCR (polymerase chain reaction) offers several advantages. It helps to detect specific pathogens that are difficult to culture in vitro or which require lengthy cultivation periods. PCR serves as a valuable screening tool and is very useful in identifying cases in extra pulmonary specimens, which may be missed by culture or smear. It provides significantly quicker results as compared to culturing, which allows scientists to make informed decisions earlier. This also helps in the rapid diagnosis of bacteremia, which is particularly useful for detecting low levels of bacteria in specimens.