Interpretation Of Results - 3M Attest 1491 Manual De Instrucciones

8. To activate the biological indicator,
place it in an Attest™ Biological
Indicator Activator. Close and
squeeze the activator to close the
1491 BI cap and crush the media
ampoule. Then remove the BI
and flick it (see pictures at right).
Visually verify that media has
flowed into the growth chamber at
the bottom of the vial. If the media
hasn't filled the growth chamber,
hold the BI by the cap and flick
it until media fills the growth
chamber. Place the activated
1491 BI:
− in any well of a 490 or 490H
Auto-reader having software
version 4.0.0 or greater
or
− in an incubation well of a
490 Auto-reader having
software version less than
4.0.0 which is color-coded
blue (i.e., configured to
incubate 1491 BIs)
or
− in any well of a 490M
Auto-reader
and wait for the result. See the
Auto-reader Operator's Manual
for further information related
to its use.
9. Each day that a processed 1491 BI is incubated, activate and incubate at least
one non-processed 1491 BI to use as a positive control. Follow the activation
instructions provided in Step 8 above. Write a "C" (for "control") and the date
on the BI label. The positive control should be from the same lot code as the
processed biological indicator. It is a good practice to use a positive control each
day a processed 1491 BI is incubated. This helps confirm:
• correct incubation temperatures are met,
• viability of spores has not been altered due to improper storage temperature,
humidity or proximity to chemicals,
• capability of media to promote rapid growth, and
• proper functioning of the Auto-reader.
10. Incubation and Reading:
Incubate the positive control and steam processed 1491 BIs in a
490 Auto-reader, a 490H Auto-reader having software version 4.0.0 or greater,
or a 490M Auto-reader. See the applicable Auto-reader Operator's Manual for
the proper use of this equipment. The Auto-reader will indicate a positive result
as soon as it is obtained. The final negative 1491 BI reading is made at:
− 24 minutes in 490 or 490H Auto-readers having software version
4.0.0 or greater and in 490M Auto-readers.
− 30 minutes in 490 Auto-readers having software version less than 4.0.0.
After the results are displayed and recorded, the 1491 BIs may be discarded.

Interpretation of Results:

Fluorescent Results
The positive control (unprocessed) 1491 BI must provide a positive fluorescent result
(+ on the Auto-reader Display). Processed 1491 BI results are not valid until the
positive control reads fluorescent positive. If the positive control reads negative (- on
the Display), check the Auto-reader Operator's Manual Troubleshooting Guide. Retest
the Auto-reader with a new positive control.
With processed 1491 BIs, a positive (+ on the Display) result indicates a sterilization
process failure. A final negative processed 1491 BI reading (- on the Display) after
the specified incubation time indicates an acceptable sterilization process.
Act immediately on any positive BI results. Determine the cause of the positive BI
following facility policies and procedures. Always retest the sterilizer and do not use
sterilizer for processing loads until three consecutive BI results are negative.
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