DK130425C

1365001 Micro-biological testing MILES LABORATORIES Inc 25 Feb 1972 [16 March 1971] 8833/72 Heading C6F [Also in Division G1] A test device for the differential or semiquantitative microbial analysis of water, milk or urine samples comprises a sterile bilulous matrix 11, Figs. 1 and 2, impregnated with nutrient medium including a colour indicator responsive to micro-organism growth e.g. triphenyl tetrazolium chloride, and 0À1-5À0 per cent by weight of the formulation of a water soluble suspending agent capable of forming a viscous colloidal suspension with an aqueous liquid when the impregnated matrix is rehydrated. The bibulous material has a known constant absorption capacity and the suspending agent is sodium alginate, polyexyethylene sorbitan mono-olente, agar, carraheen, polypeptide, linear polysaccharide or polysaccharide gum. The matrix is bonded to a holder 12 of polyethylene terephthalate through a thin layer of polyethylene 14 or double-faced adhesive tape. The matrix and attached holder are held in a polyethylene envelope 13 provided with a conventional interlocking seal lip 22. The Examples disclose nutrient media, colour indicators and suspending agents, and microbiological tests using matrices containing them.