VITEK MS Collaborative Study Outline - eBook

VITEK MS Collaborative Study

June 2019

have become visible as a yellowish film. Ideally, most of the spot’s surface will be coated with crystals.

5.8.3.11 When the VITEK MS-DS target slides have been prepared, they must be tested within 72 hours. Prepared slides should be stored at room temperature in its original packaging until they are tested. 5.8.4 Sample Preparation for Yeast Isolates 5.8.4.1 The preparation of yeast samples differs from the standard procedure in that VITEK MS-FA (formic acid treatment) is applied to the organism on the VITEK MS- DS prior to adding VITEK MS-CHCA. Care is taken not to add VITEK MS-CHCA until the VITEK MS-FA is completely dry, usually after 1 - 3 minutes. 5.8.4.2 The sample is applied to the VITEK MS-DS in the same manner as described in 5.8.3.4 to 5.8.3.6. 5.8.4.3 Add 0.5 μl of VITEK MS-FA to the sample, using a new pipette tip for each

sample. Allow for enough time (1-3 minutes) for evaporation of VITEK MS-FA before adding VITEK MS-CHCA. Once the slide is completely dry, 1.0 μl of the VITEK MS-CHCA is added to each sample.

5.8.4.4 When the VITEK MS-DS target slides have been prepared, they must be tested within 72 hours. Prepared slides should be stored at room temperature in its original packaging until they are tested. 5.8.5 Sample Preparation for Mold Isolates 5.8.5.1 Wet a sterile cotton swab using API suspension media or sterile deionized water. Depress the tip of the swab to remove excess fluid. 5.8.5.2 Collect approximately a 1-2 cm diameter of mold from the agar plate. 5.8.5.3 Suspend the collected material in a 2 mL round-bottom tube containing 900 µL of 70% ethanol. Mix using a vortex-type mixer. 5.8.5.4 Centrifuge the tube for 2 minutes at a speed between 10,000 and 14,000 x g. 5.8.5.5 Discard all of the supernatant using a pipette. Use caution to avoid dislodging the pellet. 5.8.5.6 Add 40 µL of 70% formic acid and mix using a vortex-type mixer. 5.8.5.7 Add 40 µL of acetonitrile and mix using a vortex-type mixer. 5.8.5.8 Centrifuge the tube for 2 minutes at a speed between 10,000 and 14,000 x g. 5.8.5.9 Immediately spot 1 µL of the supernatant on a VITEK MS-DS slide. Allow to dry

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