Quality Control - remel Xpect Clostridium difficile Toxin A/B Manual Del Usuario

ENGLISH
Sample Preparation
Fresh (unpreserved) Stool Specimens:
1. Add Specimen Diluent up to the line marked on the dilution tube
(0.5 ml).
a. For solid stool specimens, use a wooden applicator stick
and sample from separate areas of the specimen. Transfer
a 0.2 g (6-8 mm diameter) portion of stool to the dilution
tube.
b. For semi-solid or liquid stool specimens, use a transfer
pipette to transfer 0.2 ml (second graduated mark from the
tip) of specimen to the dilution tube.
2. Mix thoroughly and allow large particulates to settle.
3. Use a transfer pipette to dispense 0.1 ml (first molded graduated
mark from the tip) of this preparation into another dilution tube.
Stool Specimens in Cary Blair:
1. Specimens collected in modified Cary Blair transport media with
indicator are used without further dilution.
2. Mix specimen thoroughly prior to testing.
3. Use a transfer pipette to dispense 0.1 ml (first molded graduated
mark from the tip) of the specimen into a diluton tube.
BHI Broth Culture:
1. Use a transfer pipette to dispense 0.1 ml (first molded graduated
mark from the tip) of a 72-hour BHI broth culture with suspected
C. difficile into a dilution tube.
Test Procedure
1. Add 5 drops of Conjugate Reagent 1 to the dilution tube
containing the diluted specimen.
2. Add 5 drops of Conjugate Reagent 2 to the dilution tube
containing the diluted specimen.
3. Mix the contents of the tube thoroughly.
4. Use a transfer pipette to dispense 0.2 ml (second graduated
mark from the tip) of sample into the circular sample well of the
test device.
5. Read and record the test results visually after 20 minutes
according to the INTERPRETATION section. (Strong positive
results may be apparent sooner than 20 minutes.) Results are
invalid beyond 20 minutes.
INTERPRETATION OF THE TEST
Positive Result (Toxin A and/or B present):
A positive test is indicated by two black-colored lines of any intensity;
one in the TEST region and one in the control (CTRL) region. A
positive test indicates the presence of C. difficile Toxin A and/or Toxin
B in the sample.
Negative Result (Toxin A and/or B not detected):
A negative test is indicated by only one black-colored line in the
control (CTRL) region. A negative test indicates that C. difficile Toxin
A and/or Toxin B are absent or below the detection limit of the test.
Invalid Result:
An invalid result occurs when the TEST line is partial or incomplete,
or the control (CTRL) line is absent or incomplete at 20 minutes.
Control line is
absent
If invalid results occur due to restricted flow of the sample along the
membrane, the specimen should be re-tested as follows:
Re-test Specimen Preparation
Further dilute the specimen as follows:
1. Combine in a clean dilution tube:
a. 4 drops of Specimen Diluent, and
b. 0.1 ml (first molded graduated mark from the tip) of
specimen from the initial specimen preparation in
Specimen Diluent (without reagents added).
2. Mix the preparation by aspirating with the transfer pipette.
3. Use 0.1 ml of this diluted specimen preparation and repeat the
Test Procedure.

QUALITY CONTROL

Internal: A procedural control is included in the test. The appearance
of a control line in the CTRL region verifies that an intact conjugate
has been added to the device, that the control line antibody is
functionally active, and that adequate capillary flow has occurred. A
clear background in the results area is considered an internal
negative control. If the test has been performed correctly and
reagents are working properly, the background will clear to give a
discernible result.
External: The Positive and Negative Quality Controls provided with
the kit should be run with each shipment and new kit lot number
received. The Positive Control is used to verify reactivity of the
reagents associated with the assay and is not intended to ensure
precision at the analytical assay cut-off.
follow their state and local requirements. To use, add 0.1 ml (5
drops) of the control to a dilution tube and process in accordance with
Test Procedure outlined above (do not dilute controls with specimen
diluent). If aberrant quality control results are noted, patient results
should not be reported.
LIMITATIONS
1. A positive test does not define the presence of disease. The
test detects the presence of Toxin A and/or Toxin B in fecal
specimens. Results should be used in conjunction with other
clinical findings to establish a diagnosis.
2. As with all in vitro diagnostic tests, a negative test result does
not exclude the possibility of the presence of C. difficile Toxin A
or Toxin B. This may occur when the toxin level in the sample is
below the detection level of the test. The level of toxin has not
been shown to correlate with either the presence or severity of
disease. Test results should be interpreted by a physician in
light of other laboratory results and clinical findings.
3. Clostridium sordellii is not a common inhabitant of the human
intestine but does produce a toxin (HT) that has biological,
physiochemical, and immunochemical properties similar to
C difficile Toxin A. This similarity may cause cross-reactivity in
any diagnostic test that detects C. difficile Toxin A and/or B.
2
Control or Test line is partial
or incomplete
Each laboratory should
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