Abstract: Devices, kits, and methods are provided for analyzing a sample for the presence or amount of a bacterium in a sample, and for determining whether or not conditions present while practicing the invention allow for accurate test results. Specifically, the invention provides devices, kits, and methods for analyzing a sample for the presence or amount of a bacterial carbohydrate, while using an analog of the bacterial carbohydrate as a control reagent. In certain embodiments, the invention may provide for analyzing a sample for the presence or amount of a Group A Streptococcus (GAS) bacterium, by determining the presence or amount of ?-N-Acetyl-D-Glucosamine attached to a poly-rhamnose backbone, a bacterial carbohydrate found in GAS, in the sample, and by using Albumin, Bovine, p-Aminophenyl N-Acetyl B-D Glucosaminide, an analog to ?-N-Acetyl-D-Glucosamine as a control reagent.