3M VH202 Manual De Instrucciones página 6

9. Each day that a processed 1295 BI is incubated,
activate and incubate at least one non‑processed
1295 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. The
positive control BI 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 processed
1295 BIs at 60 ± 2°C in a 490H Auto‑reader or
490 Auto‑reader having software version 4.0.0 or
greater. See the 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 1295 BI reading is made at:
‑ 24 minutes in 490H or 490 Auto‑readers having
software version 4.0.0 or greater
‑ 4 hours in 490H Auto‑readers having a software
version less than 4.0.0.
After the results are displayed and recorded, the
1295 BIs may be discarded.
Fluorescent Result
The positive control (unprocessed) 1295 BI must
provide a positive fluorescent result (+ symbol on
the 490H Auto‑reader or 490 Auto‑reader having
software version 4.0.0 or greater LCD display).
Processed 1295 BI results are not valid until the
positive control reads fluorescent positive. If the
positive control reads negative (‑ symbol on the LCD
display), check the Auto‑reader Operator's Manual
Troubleshooting Guide. Retest the 490H Auto‑reader
or 490 Auto‑reader having software version 4.0.0 or
greater with a new positive control.
With processed 1295 BIs, a final negative reading
(‑ symbol on the LCD display) indicates an acceptable
sterilization process. A positive (+ symbol on the LCD
display) result for a processed 1295 BI indicates a
sterilization process failure. Act immediately on any
positive results for processed BIs. Determine the
cause of the positive BI following facility policies and
procedures. 3M recommends retesting the sterilizer
according to your facility policy before processing
additional loads.
Optional Visual pH Color Change Result
The 1295 BI is normally discarded after the fluorescent
result has been recorded. If, however, special studies
are desired, 1295 BIs may be further incubated for
a visual pH color change result. In the case of the
positive control BI, a yellow color change of the growth
media will appear within 24 hours. Any observation of
a yellow color within the vial indicates a positive result.
In the case of a processed 1295 BI, a media color
change from purple to yellow indicates a sterilization
process failure. A negative pH color change result,
i.e., media remains purple, can be assessed at 7 days.
To avoid media dry‑out, it is recommended that the
1295 BI be transferred to a humidified incubator
operating at 60ºC after the fluorescent result has
been recorded.
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