The latex particles of the PathoDxtra grouping reagents are coated in relevant specific antibodies. These react with any corresponding Streptococcal group antigen extracted from the bacterial cell wall, causing agglutination. The test works with as little as one, but up to four, colonies of an 18 to 24 hour culture of β-hemolytic Streptococcal isolates. Rapid reactions are due to group-specific antigen being extracted instantaneously using the room-temperature, nitrous acid extraction procedure. Once neutralized, the extracted antigen is tested against specific IgG-coated latex particles on a test slide. The distinct and easily recognizable granular agglutination pattern of a positive test contrasts markedly with the uniform, milky appearance of a negative result, making the test simple to interpret. The latex particles of the PathoDxtra grouping reagents are coated in the relevant specific antibodies. These react with any corresponding streptococcal group antigen extracted from the bacterial cell wall, causing agglutination. The test works with as little as one, but up to four, colonies of an 18 to 24 hour culture of β-hemolytic streptococcal isolates. Rapid reactions are due to group-specific antigen being extracted instantaneously using the room-temperature, nitrous acid extraction procedure. Once neutralized, the extracted antigen is tested against specific IgG-coated latex particles on a test slide. The distinct and easily recognizable granular agglutination pattern of a positive test contrasts markedly with the uniform, milky appearance of a negative result, making the test simple to interpret.

General References:

1. Murray, P.R., Baron, E.J., Jorgensen, J.H. et al. (2003) Manual of Clinical Microbiology. 8th ed., Vol 1. ASM, Washington, D.C.

2. Evins, G.M., et al. (1983) The development by the Centers for Disease Control of a specification for streptococcal serogrouping kits and its application to Streptex and to the Phadebact Streptococcus Test. J. Biol. Standard. 11:333-339.

3. Facklam, R.R., et al. (1979) Evaluation of commercial latex agglutination reagents for grouping streptococci. J. Clin. Microbiol. 10:641-646.

4. Slifkin, M., and Pouchet-Melvin, G.R. (1980) Evaluation of three commercially available test products for serogrouping betahemolytic streptococci. J. Clin. Microbiol. 11:249-255.