Patent ID: 7745169

Claim:
A test kit for selectively and simultaneously detecting the presence of primary and secondary groups of microorganisms in a test sample, the test kit comprising: a container configured to receive the test sample, the container made of material transparent to visible light and ultraviolet light in a specific spectral band; a mixture of materials contained in said container, the mixture of materials including growth media compounded to promote growth of both the primary and secondary groups of microorganisms, a chromogenic substrate material capable of selectively indicating growth of the primary groups of microorganisms, and a fluorogenic substrate material capable of selectively indicating growth of the secondary group of microorganisms; and a photo reader, the photo reader consisting of: a visible light source generating electromagnetic energy directed through said transparent material of the container, the visible light source interacting with said chromogenic substrate to yield chromogenic interaction light indicative of growth of the primary groups of microorganisms; an ultraviolet light source generating electromagnetic energy directed through said transparent material and interacting with said fluorogenic substrate to yield fluorogenic interaction light indicative of growth of the secondary groups of microorganisms; and a single photo detector, capable of detecting said chromogenic interaction light and fluorogenic interaction light and producing detection signals respective to said chromogenic interaction light and said fluorogenic interaction light; and a controller electronically connected to the visible light source associated with the container, the ultraviolet light source associated with the container, and the single photo detector, the controller configured to switch the respective light sources on and off in a sequential order; wherein said chromogenic and fluorogenic substrates are selected to enable the fluorogenic substrate to indicate the growth of the secondary group of microorganisms while the primary group of microorganisms is simultaneously growing and changing the color of said chromogenic substrate.