Abstract: A plurality of petri dishes or other glass or plastic containers are coated on the inside bottom surface of the containers by passing the containers through a coating or layering apparatus. The apparatus includes an indexing conveyor to sequentially pass the open containers through a filling station where an amount of a coating material is applied while tilting the container to one side thereby distributing the material to the entire bottom surface of the container. The containers are conveyed to an aspirating station to aspirate excess material while tilting the container toward the aspirating nozzle. Subsequent to the aspiration step, the containers are tilted in the opposite direction to distribute the material in the container. The material is then dried and the containers stacked and packaged. The coating material includes metal ions such as calcium or other divalent metal ions, in a suitable carrier that is able to bond the bottom inside surface of the container.

Abstract: A chromogenic .beta.-galactosidase substrate producing an insoluble precipitate of a first color when reacted upon by .beta.-galactosidase and a chromogenic .beta.-glucuronidase substrate producing an insoluble precipitate of a second, contrasting color when reacted upon by .beta.-glucuronidase are combined in a test medium for quantitatively identifying and differentiating general coliforms and E. coli. The .beta.-galactosidase substrate 5-bromo-4-chloro-3-indolyl-.beta.-D-galactopyranoside which produces an indigo blue precipitate when reacted upon by .beta.-galactosidase may be used with one of the novel compounds 6-chloroindolyl-.beta.-D-glucuronide, 4,6-dichloroindolyl-.beta.-D-glucuronide, 6,7-dichloroindolyl-.beta.-D-glucuronide, and 4,6,7-trichloroindolyl-.beta.-D-glucuronide, which produce mauve or magenta precipitates when reacted upon by .beta.-glucuronidase. The .beta.-glucuronidase substrate 5-bromo-4-chloro-3-indolyl-.beta.

Abstract: A chromogenic .beta.-galactosidase substrate producing an insoluble precipitate of a first color when reacted upon by .beta.-galactosidase and a chromogenic .beta.-glucuronidase substrate producing an insoluble precipitate of a second, contrasting color when reacted upon by .beta.-glucuronidase are combined in a test medium for quantitatively identifying and differentiating general coliforms and E. coli. The .beta.-galactosidase substrate 5-bromo-4-chloro-3-indolyl-.beta.-D-galactopyranoside which produces an indigo blue precipitate when reacted upon by .beta.-galactosidase may be used with one of the novel compounds 6-chloroindolyl-.beta.-D-glucuronide, 4,6-dichloroindolyl-.beta.-D-glucuronide, 6,7-dichloroindolyl-.beta.-D-glucuronide, and 4,6,7-trichloroindolyl-.beta.-D-glucuronide, which produce mauve or magenta precipitates when reacted upon by .beta.-glucuronidase. The .beta.-glucuronidase substrate 5-bromo-4-chloro-3-indolyl-.beta.

Abstract: A method for preparing a gelled biological growth medium which comprises combining a liquid growth medium and low methoxyl pectin material to a culture-growth container having a growth-compatible gel including a multivalent metal cation material therein, the pectin material being the sole or essentially the sole functional gelling agent of the growth medium gel.

Abstract: A method for preparing a gelled biological growth medium in a culture growth container which comprises combining a liquid growth medium including low methoxyl pectin and a multivalent metal cation material in the culture growth container. Preferably, the cation material is located on a support material, such as a filter pad or paper, and the liquid growth medium including the low methoxyl pectin material is poured over the support material while in the culture growth container.