Strep A

The NADAL® Strep A Test is a rapid visual immunoassay for the qualitative, presumptive detection of group A Streptococcus antigens (Strep A) in human throat swab specimens. The test is intended for use as an aid in the diagnosis of Strep A infections in patients showing typical symptoms. The test is designed for professional use only. 

Beta-hemolytic group A Streptococcus is a major cause of upper respiratory infections such as tonsillitis, pharyngitis and scarlet fever. Early diagnosis and treatment of Strep A pharyngitis has been shown to reduce the severity of symptoms and further complications, such as rheumatic fever and glomerulonephritis. 

Conventional methods for detecting Strep A infection are dependent on isolation and subsequent identification of the organism and often require 24-48 hours. Recent developments in immunological techniques to detect Strep A antigens directly from throat swabs support physicians in diagnosing Strep A infections and administering a therapy immediately. 

The NADAL® Strep A Test enables the detection of group A Streptococcus antigens through visual interpretation of colour development on the internal test strip. Anti-Strep A antibodies are immobilised in the test line region of the membrane. During the test, the specimen reacts with the polyclonal anti- Strep A antibodies conjugated to coloured particles and precoated onto the sample pad of the test cassette. The mixture then migrates along the membrane by capillary action and interacts with the reagents on the membrane. If there are sufficient Strep A antigens in the specimen, a coloured line will form in the test line region of the membrane. The presence of this coloured line indicates a positive result, while its absence indicates a negative result. The appearance of a coloured line in the control line region serves as a procedural control, indicating that the proper volume of specimen has been added and membrane wicking has occurred.