Technical Note
BioFire Diagnostics, LLC
www.BioFireDX.com
FLM1-PRT-0230-02
TECHNICAL
::: NOTE
Contamination Prevention and
Decontamination
Introduction
FilmArray® is an automated in vitro diagnostic (IVD) system that utilizes nested
multiplex PCR (nmPCR) and high-resolution melting analysis to detect and
identify multiple nucleic acid targets from clinical specimens.
Polymerase chain reaction (PCR) is the process of making millions of copies of
DNA by amplifying a specific DNA region. A common concern with PCR-based
methods is false positive results caused by contamination. Contamination is the
introduction of organisms or amplicons into specimens during collection or
handling, or introduced into reagents during the testing process.
This document provides guidelines for preventing or eliminating sources of
contamination while performing FilmArray tests.
Contamination Prevention
Preventing Organism Contamination
Healthcare workers can be infected or colonized with organisms detected by the
FilmArray and may inadvertently contaminate the sample during collection or
processing. Organisms can be carried asymptomatically, particularly on skin and
mucosal surfaces.
During sample collection, healthcare workers are advised to wear a
surgical mask (or equivalent) and avoid touching the mask while
collecting specimens. In particular, wearing a mask can help prevent
contamination from:
a. Individuals with active respiratory symptoms (runny nose, cough,
etc)
b. Individuals with active or latent HSV-1 infection (i.e. Cold sore).
c. Healthy individuals who may actively shed S. pneumoniae, H.
influenzae as well as other organisms.
Do not collect or process specimens in areas that are exposed to
vaccine material targeting pathogens that may be detected by FilmArray
panels (e.g. Rotavirus, Bordetella pertussis, etc). Some Bordetella
pertussis acellular vaccines (i.e. Pentacel®, Daptacel®, and Adacel®)
contain PCR detectable DNA. Contamination of specimens or testing
materials with vaccine can cause false positive B. pertussis results.
(http://www.cdc.gov/pertussis/clinical/diagnostic-testing/diagnosis-pcrbestpractices.html.
Process specimens and load pouches in a biosafety cabinet. If a biosafety
cabinet is not used, a dead air box (e.g., AirClean PCR workstation), a
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Technical Note
BioFire Diagnostics, LLC
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TECHNICAL
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splash shield (e.g., Bel-Art Scienceware Splash Shields), or a face shield
should be used when preparing specimens.
A biosafety cabinet used to perform viral, bacterial, or fungal culture
should not be used for specimen preparation or FilmArray reagent setup.
Prior to processing specimens, thoroughly clean both the work area and
the FilmArray Pouch Loading Station using a suitable cleaner such as
freshly prepared 10% bleach solution (1-part bleach to 9-parts water) or
a similar disinfectant effective against potential nucleic acid
contamination. To avoid residue build-up and potential PCR inhibition,
wipe disinfected surfaces with distilled water.
WARNING: Bleach should never be added to Sample Buffer or sample
waste.
Handle specimens and FilmArray pouches one-at-a-time. Completely set
up a single FilmArray test and start the run before moving to the next
specimen.
Clean the work area between each specimen.
Change gloves between each specimen. Change gloves during testing if
you have touched your face or other potentially-contaminated surface.
Preventing Amplicon Contamination
The FilmArray pouch is a closed system. Therefore, the risk of amplicon
contamination is low, provided that pouches remain intact after the test is
completed. Adhere to the following guidelines to prevent amplicon contamination:
Discard used pouches in an appropriate biohazard container immediately
after the run has completed.
Avoid excessive handling of pouches after test runs.
Avoid exposing pouches to sharp edges or anything that might cause a
puncture.
WARNING: If liquid is observed on the exterior of a pouch, the liquid and
pouch should be immediately contained and discarded in a biohazard
container. Treat all broken pouches as capable of contaminating your work
area. The instrument and workspace must be decontaminated as described in
the Decontamination and Cleaning Procedures section below. Do not perform
additional testing until the area has been decontaminated.
Suspected False Positive Results Caused by Contamination
When false positive results caused by contamination are suspected an external
negative control should be run as follows:
1. Test a negative sample by preparing a pouch using a fresh sample buffer
ampoule and Sample Injection Vial without the addition of a patient
specimen or control material.
2. If unexpected positive results are obtained, decontamination and cleaning
procedures should be completed. After decontamination is completed, test
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Technical Note
BioFire Diagnostics, LLC
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FLM1-PRT-0230-02
TECHNICAL
::: NOTE
an additional pouch as described in step 1. If unexpected positive results
are obtained, call BioFire Technical Support.
3. Swab testing. (Refer to the Swab test procedure below)
Decontamination and Cleaning Procedures
The following decontamination and cleaning procedures are recommended to be
followed as a general practice for preventing contamination and/or when false
positive result potentially caused by contamination are suspected. Additionally, the
following decontamination and cleaning procedures are recommended if an event
that may have resulted in potential or suspected contamination of the work area
occurs (i.e. sample spill, reagent pouch leak or breakage). Decontamination is
necessary to prevent false-positive results in subsequent runs.
Change gloves often during the decontamination process and before touching any
clean surface. All personal protective equipment (PPE) should be discarded after
decontamination.
Cleaning Materials
This list provides items that are necessary in a laboratory to keep contamination
to a minimum.
10% bleach solution in a squeeze or spray bottle (1-part bleach to 9-parts
water) – mix a fresh solution frequently (daily is recommended).
Distilled water in a squeeze or spray bottle
DNAZap™or equivalent DNA degradation reagent
Paper towels
Bleach wipes
CAUTION: Do not use decontamination or cleaning agents that could cause
a hazard as a result of a reaction with parts of the equipment or with material
contained in it. If you are unsure whether a cleaning agent will react negatively
with the parts of the equipment or with the materials contained in it contact
BioFire Diagnostic’s Technical Support or an authorized distributor.
Decontamination of the Pouch Loading Station
The Pouch Loading Station can be submerged for decontamination:
1. Put on a lab coat and gloves.
2. Rinse the Pouch Loading Station with water.
3. Fill a sink or bin with water and add bleach to create a 10% bleach solution
(1-part bleach to 9-parts water).
4. Submerge the Pouch Loading Station until completely covered with bleach
solution. Soak for 15 minutes.
5. Remove Pouch Loading Station from sink or bin. Replace bleach solution
with water.
6. Rinse the Pouch Loading Station by completely submerging in water two
additional times.
Decontamination Related to Pouch Leakage
1. Put on clean PPE such as gloves and safety shield.
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2. Ensure potentially-contaminated areas or instruments are not used
3. Decontaminate and dispose of the pouch using the following steps:
a. Dispose of potentially contaminated gloves and put on clean
gloves.
b. Dispose of the potentially contaminated lab coat and put on a
clean lab coat.
c. Discard pouch in biohazard waste container.
d. Change gloves.
e. Follow decontamination procedures for cleaning affected areas
(See below)
Instrument Pouch Loading Chamber Decontamination
1. Put on a lab coat and gloves.
2. Remove pouch from instrument and discard in biohazard waste
container.
3. Wipe the area to be decontaminated with water.
4. Wet a paper towel with 10% bleach (1-part bleach to 9-parts water) and
wipe the surface of the inner sample chamber and under the lid.
5. Change gloves.
6. Repeat steps 3 to 5 twice with fresh paper towels for a total of three
bleach wipes.
7. Wet a paper towel with distilled water and wipe sample chamber.
8. Change gloves.
9. Repeat step 7 with fresh paper towel.
Decontamination of Bench Tops and Other Areas
1. Put on a clean lab coat and gloves.
2. Wipe the area to be decontaminated with water.
3. Wipe the suspected area with a paper towel soaked in 10% bleach
solution (1-part bleach to 9-parts water). Let it stand for 5 minutes.
4. Change gloves.
5. Repeat step 3 and 4 twice, for a total of three wipes.
6. Spray the area with distilled water.
7. Wipe the area dry with a new paper towel.
8. Change gloves.
9. Spray the area with DNAZap or an equivalent product. Follow the
product’s instructions for correct use.
10. Change gloves.
11. Rinse the area by spraying it with distilled water and wiping it dry.
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Technical Note
BioFire Diagnostics, LLC
www.BioFireDX.com
FLM1-PRT-0230-02
TECHNICAL
::: NOTE
Swab Test
Environmental Swab Testing can be used to monitor for potential contamination
that may compromise the FilmArray test results Swab testing may be conducted
at regular intervals and/or when contamination is suspected. The frequency of
swab testing should be determined by the Laboratory Director.
Decontaminate all work surfaces used for FilmArray testing including:
bio-safety cabinet surfaces, Pouch Loading Stations, and FilmArray
instrument using the procedure above.
WARNING: Bleach is a known PCR inhibitor. Residue must be adequately
removed with distilled water wipes or swab tests may fail.
Change gloves before beginning swab testing.
Obtain sterile 1.5 mL microcentrifuge tubes or equivalent.
Fill the microcentrifuge tube with approximately 500 µL of molecular
grade water.
Unwrap two individually-packaged sterile flocked swabs or equivalent
and place them into the tube; allow the swabs to sit for approximately 1
minute.
Use the wet swabs to swab work surfaces used for FilmArray specimen
setup and testing.
Place the swabs in the Sample Injection Vial. Remove or break-off
excess swab stick so that the Sample Injection Vial may be closed.
Invert Sample Buffer Ampoule so that tip is facing up.
o Do not touch the tip of the ampoule.
Firmly pinch textured plastic tab on side of ampoule until seal snaps.
With the tip facing down, dispense Sample Buffer into Sample Injection
Vial using a slow, forceful squeeze, followed by a second squeeze. Avoid
generating excessive bubbles.
Tightly close lid of Sample Injection Vial. Unscrew Hydration Injection
Vial, leaving cap in Pouch Loading Station,
o Insert Hydration Injection Vial into pouch hydration port.
o Forcefully push down to puncture seal.
o Wait as Hydration Solution is drawn into pouch.
Mix sample by gently inverting Sample Injection Vial 3 times.
Unscrew Sample Injection Vial from cap.
o Pause for 3-5 seconds, then remove Sample Injection Vial,
leaving cap in Pouch Loading Station.
o Insert Sample Injection Vial into pouch sample port.
o Forcefully push down to puncture seal.
o Wait as Sample Mix is drawn into pouch.
Follow instructions on the FilmArray computer for initiating a test.
Swab samples should be tested immediately after swab collection.
Results of the swab test should be negative for all organisms (and the
pouch controls should pass).
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Technical Note
BioFire Diagnostics, LLC
www.BioFireDX.com
FLM1-PRT-0230-02
TECHNICAL
::: NOTE
Technical Support Contact Information
BioFire is dedicated to providing the best customer support available. If you
have any questions or concerns about this process, please contact the FilmArray
Technical Support team for assistance.
BioFire Technical Support
Email: support@biofiredx.com
Phone: +1-801-736-6354, select Option 5 and then Option 1
For FilmArray technical assistance and support outside of the US, please contact
your local bioMérieux representative or authorized distributor.
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