| abstract |
For simultaneous control of cleaning and hygiene, in particular in the food industry and hospitals, an aqueous solution of an optionally fluorescent dye or a combination of such dyes which bind on organic material, including microorganisms, and colour them in the process is applied onto the surfaces which are to be cleaned. An organic contamination, if any, of the surfaces will then show itself by colouring thereof. Among the usable dyes the disodium salt of 2,4,5,7-tetraiodofluorescein is preferred. Hereby the disadvantages attached to the known methods of controlling the hygiene level at work sites and in institutions are avoided, in particular the time delay of as much as 4 days caused by the fact that samples taken out must first be incubated. By the method of the present invention immediate information about the state of the hygiene is obtained. |