SKC 560-002 MethChek Immunoassay Wipe Kit - Manual (Page 7)

7
Reading MethChek Results
Ensure sample well on cartridge is on the right as shown below.
Observe results. Step 3 Cartridge results will remain visible for several months
before fading. Photograph cartridge results if required.
Negative Results
Q: I see two lines on the cartridge, but one of the lines is faint. Is this a negative
result?
A: The appearance of a faint line with a dark line indicates a negative test. The
appearance of two lines, regardless of intensity, is a negative test.
Invalid Test
Invalid test results are a rare occurrence. Possible causes for an invalid result
can include: damaged test cartridge, storage at high temperatures, expired test
cartridges, interferences in the sample (strong organics, bleaching agents, extremely
high or low pH), or improper test procedure (cartridge not held fl at during
development, insuffi
cient sample volume). If an invalid test result appears, perform
a new test with a new cartridge.
If no lines appear on the Step 3 Cartridge, it may be due to one of the following:
insuffi
cient volume of extract liquid was added to the Step 3 Cartridge or extract
liquid was added to the sample window instead of the sample well (marked “S”)
on the Step 3 Cartridge.
Protect developed cartridges from bright light. Bright light will cause
cartridge results to fade over time (not aff ected by indoor lighting).
Line density (faintness or darkness) is not equivalent to concentration.
Negative
Meth residue not detected
at kit lower limit of identifi cation
Invalid test
Perform new test
Positive Negative Invalid
Positive
Meth residue detected
above kit lower limit
of identifi cation
Sample
well
Sample
well
Sample
well