Run An Additional Toxin Test At A 1:40 Dilution; Dilution Procedure (1:40 Dilution) - Guardian R1000 Operation Manual

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Appendix I

** These samples may need to be further diluted from the original sample

preparation if the concentration of the solution is high enough to clog the filter on the

test strip. Visibly excessive red streaking or an incomplete Control Line is evidence of

a very high sample concentration. Follow Dilution Procedure (below) if necessary.

Dilution Procedure: (1:4 dilution)

Run an additional toxin test at a 1:40 dilution

Because of the high sensitivity of the toxin test strips and the nature of the im-

munoassay's response curve, care must be taken not to over-sample a toxin and to

generate a false negative result. Because of this, it is necessary for users to always

run an additional test whenever using ricin, botulinum toxin, abrin or SEB tests. The

second test should be run at a 1:40 dilution. No additional test is normally required

when running anthrax, plague, tularemia, orthopox or brucella.

Use care in sampling. Approximately a microgram of material in one milliliter

of buffer solution is sufficient to run 6 tests. When testing for toxins (ricin, bot. toxin

or SEB), always run a second test strip, using a 1:40 dilution of the original sample.

Add 1 ml of Sample Buffer into a fresh vial.

Using a disposable bulb dropper, remove liquid from top liquid layer of the

original sample vial.

Add 0.25 ml to the fresh sample vial.

Mix solution by inverting 5 times. Allow any particles to settle to the bot-

tom of the vial (30-60 seconds).

Using a fresh disposable bulb dropper, remove liquid from top liquid layer

(below any foam) of the sample vial being careful not to pull up particles

that have settled to the bottom.

Using the disposable dropper, place 5-7 drops into the sample port (3-5

drops if using the Alexeter Collection Swab), filling the sample port com-

pletely within a period of 3-4 seconds. When properly dosed, a red liquid

will begin moving across the test strip within 20 seconds.

Repeat dilution procedure if new test sample is still too viscous to run prop-

erly on another test strip.

Start with your original sample in buffer solution.

Add one milliliter of buffer solution to a new, clean vial.

Add one drop of the original sample to this vial and agitate for 10 seconds.

Dose the additional toxin strip(s) with the 1:40 dilution.

Evaluate the tests as per our standard protocol. See the Guardian Reader

Manual and the Guardian Reader Testing Flow Chart for details.

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