VITEK MS Collaborative Study Outline - eBook

VITEK MS Collaborative Study

June 2019

2.3.8 It is strongly recommended to deposit the matrix as indicated in the VITEK MS Prep Station workflow for bacteria: 2 by 2 in duplicate mode Note: The VITEK MS-CHCA matrix contains a high concentration of organic solvents; it is recommended to close the tube after dispensing to avoid evaporation. 2.3.9 Proceed likewise for each additional sample. 2.3.10 After five minutes, check for crystal formation on the spots. Use of a magnifying lens may be helpful. An accurate measurement requires that the matrix crystals have become visible as a yellowish film. Ideally, most of the spot’s surface will be coated with crystals. 2.3.11 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. 2.4 Sample Preparation for Yeast Isolates 2.4.1 The preparation of yeast isolates 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. 2.4.2 The sample is applied to the VITEK MS-DS in the same manner as described in 5.8.2.4 to 5.8.2.6. 2.4.3 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 spot is completely dry, 1.0 μl of the VITEK MS-CHCA is added to each spot. 2.4.4 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.

2.5

Sample Preparation for Mold Isolates 2.5.1 Wet a sterile cotton swab using API suspension media or sterile deionized water. Depress the tip of the swab to remove excess fluid. 2.5.2 Collect approximately a 1-2 cm diameter of mold from the agar plate. 2.5.3 Suspend the collected material in a 2 mL round-bottom tube containing 900 µL

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