Draft
June
2003
E.
coli
Most
Probable
Number
Sample
Results
Acceptability
Checklist
for
the
LT2
Rule
No.
Factor
Check
sample
results
to
verify
that:
U
Sample
Condition
1
Sample
condition
upon
receipt
The
sample
temperature
upon
receipt
for
the
sample
was
between
0
°
C
and
10
°
C,
and
the
sample
was
not
frozen
or
leaking
Holding
Time
and
Temperature
2
Holding
time
and
temperature
The
sample
was
analyzed
within
24
hours
of
sample
collection
and
maintained
at
<
10
°
C,
but
not
freezing,
between
collection
and
analysis
General
Quality
Control
3
Dilution/
rinse
water
sterility
check
The
dilution/
rinse
water
sterility
check
was
acceptable
(
target
organism
or
potentially
interfering
materials
were
not
found
in
the
sterility
check)

4
Media
sterility
check
The
media
sterility
check
was
acceptable
(
target
organism
or
potentially
interfering
materials
were
not
found
in
the
sterility
check)

5
Positive/
negative
controls
The
positive/
negative
controls
were
acceptable
6
Media
storage
specifications
The
media
storage
specifications
were
not
exceeded
Most
Probable
Number
QC
Specifications
7
Incubation
time
and
temperature
The
following
incubation
time
and
temperature
requirements
were
not
exceeded:
Colilert
24
­
28
hours
at
35
°
C
±
0.5
°
C
Colilert­
18
18
­
22
hours
at
35
°
C
±
0.5
°
C
LTB
24
±
2
or
48
±
3
hours
at
35
°
C
±
0.5
°
C
EC­
MUG
24
±
2
hours
at
44.5
°
C
±
0.2
°
C
8
Preparation
blank
The
preparation
blank
was
not
contaminated
with
the
target
organism
9
Verification
of
positive
results
The
verifications,
performed
in
accordance
with
method­
specific
requirements,
were
acceptable
