quellung reaction

The Quellung reaction is a laboratory test used to identify specific bacteria, especially those causing pneumonia and meningitis. It involves adding antibodies that recognize and bind to the bacteria’s capsule, a protective outer layer. When these antibodies attach, they cause the capsule to swell or become visible under a microscope, making the bacteria easier to see and identify. This reaction helps doctors quickly determine the bacterial type, guiding appropriate treatment decisions. It’s a valuable tool in microbiology for diagnosing infections caused by certain bacteria like Streptococcus pneumoniae.