The present invention is directed to a method and a test kit for detecting cockroach allergens and/or determining the total allergen level. A sample from an environment in which cockroaches are present or are suspected to be present is provided. The sample and a substrate composition comprising a chitinase substrate are then contacted. The presence of cockroach allergens can be determined by observing or detecting the magnitude of a measurable change of a property of the substrate composition following the contact between the sample and the substrate composition wherein the magnitude of the measurable change of a property of the substrate composition is proportional to the total allergen level. The total allergen level can be determined by measuring the magnitude of the measurable change of a property of the substrate composition, or by comparing the magnitude with a reference standard.