1. SCIENTIFIC
How to know EXPLANATION
PROCEDURE:
if water is The DBC reagent containing the
chromogenic substrate
clean? enzyme 5-bromo-4-chloro-3-
indolyl-B-D galactopyranoside
(X-GAL) • Take the sample
for the detection of ß- to the flask to
galactosidase (an enzyme
Step 1 100ml.
-Andrea F. indicative of
coliform). In the hydrolysis of ß-
#9 Dgalactosidasa.
X-GAL off a chromogenic • Pour the
compound (indigo-blue) contents of the
-Alicia Rdz makes the medium turns from powder in the
#23
yellow to blue-green.
It also contains the fluorogenic
Step 2 vial with the
sample.
substrate of the enzyme
-Pamela Mtz 4-methyl-umbelliferil-bd-
glucuronide (MUG) for • Stir until the
# 21
powder
detecting completely
ß-glucuronidase (an enzyme integrated.Incubat
-Cristina Gzz specific for E. coli). In hydrolysis
ß-glucuronidase, MUG clear 4-
Step 3 e at 35 2 ° C from
18 to 24 hours.
#13 methylumbelliferone
which fluoresces when exposed
-Andrea Hdz to ultraviolet light.
The fluorescence distinguishes
the presence of E. coli group
#16 coliform.
Take the sample in the vial

2. What it is What is going to
about: happen is that the
Selective enrichment BCD powder
medium and suppose to
differential identify if the
for the detection of water is clean or is
microorganisms of the
group
not.
coliforms in various
products and to Conclusions:
investigate If after all the
the presence of E. procedure the
coli by fluorescence water is green it
and testing
means is not
confirmatory by
indole. clean but if its
yellow is clean.