Method Description

The BinaxNOW Streptococcus pneumoniae test is an immunochromatographic membrane assay used to detect pneumococcal-soluble antigen in cerebrospinal fluid. Rabbit anti-Streptococcus pneumoniae and anti-species antibodies are conjugated to visualizing particles that are dried onto an inert fibrous support. The resulting conjugate pad and the striped membrane are combined to construct the test strip.

To perform the test, a swab is dipped into the specimen, removed, and then inserted into the test device. Reagent A, a buffer solution, is added from a dropper bottle. The device is then closed, bringing the sample into contact with the test strip. Pneumococcal antigen present in the sample reacts to bind anti-Streptococcus pneumoniae conjugated antibody, forming the sample line. Immobilized control antibody captures anti-species conjugate forming the control line.

Test results are interpreted by the presence or absence of visually detectable pink-to-purple-colored lines. A positive test result, read in greater than or equal to 15 minutes depending on the concentration of antigen present in the sample, will include the detection of both a sample and control line. A negative test result, read in 15 minutes, will produce only a control line, indicating that Streptococcus pneumoniae antigen was not detected in the sample. Failure of the control line to appear, whether the sample line is present or not, indicates an invalid assay.(Package insert: BinaxNOW Streptococcus pneumoniae Test. Abbott; 01/15/2020)