N-acetyl-D-glucosamine for enhanced specificity of Strep A immunoassay
View Patent ↗Methods, compositions and kits for detecting Group A streptococcus in a biological sample are described. More particularly, the present disclosure provides an immunoassay in which the specificity of detection of Group A streptococcus is enhanced by addition of N-acetyl-D-glucosamine. These methods, compositions and kits are useful in convenient, reliable and early diagnosis of streptococcal infection in a human subject.
1. A device, comprising: a matrix comprising (i) a sample receiving zone, (ii) a labeling zone containing a labeled antibody with specific binding to Group A streptococcus antigen, to form a labeled antibody-bound antigen, and (iii) a capture zone having means for specifically binding the antibody-bound antigen thereon, wherein the sample receiving zone, the labeling zone and the capture zone are arranged on the matrix in a liquid flow path, and wherein at least one of the sample receiving zone and the labeling zone comprises N-acetyl-D-glucosamine (NAG) monomer which reduces the rate of false positives for providing accurate detection of Group A streptococcus infection.
2. The device of claim 1 , wherein the antibody is a polyclonal antibody.
3. The device of claim 2 , wherein the antibody is fluorescently labeled.
4. The device of claim 1 , wherein the means for specifically binding the antigen-bound antibody is a capture antibody.
5. The device of claim 4 , wherein the capture antibody is a polyclonal antibody.
6. A method for detecting the presence or absence of Group A streptococcus in a biological sample, comprising:
providing a device according to claim 1 ;
placing a biological sample on the device; and
determining the presence or absence of Group A streptococcus.
7. The method of claim 6 , further comprising:
providing an instrument for collecting the biological sample; and
collecting a biological sample on the instrument.
8. The method of claim 6 , further comprising:
providing instructions for use, wherein the instructions do not caution to not touch the tongue, sides or top of mouth with the instrument when collecting the sample.