| 摘要 |
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 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 -D-glucuronide, which produces an indigo blue precipitate when reacted upon by beta -glucuronidase may be used with one of the novel compounds 6-chloroindolyl- beta -D-galactoside, 4,6-dichloroindolyl- beta -D-galactoside, 6,7-dichloroindolyl- beta -D-galactoside, and 4,6,7-trichloroindolyl- beta -D-galactoside which produce mauve or magenta precipitates when reacted upon by beta -galactosidase.
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