Method Description Describes how the test is performed and provides a method-specific reference
Free and total carnitine are measured by tandem mass spectrometry (MS/MS) stable isotope dilution analysis. Hydrolysis enables measurement of total carnitine, and esterified carnitine (acylcarnitine) is calculated as the difference between the total and free carnitine. Quantification is enabled using deuterium-labeled carnitine (d3-carnitine) added as internal standard. A selected reaction monitoring experiment is performed by MS/MS. The first mass spectrometer (Q1) detects carnitine and d3-carnitine precursors, and transmits them to a collision cell (Q2) within the mass spectrometer where they are fragmented. Specific fragments derived from the carnitine and internal standard are monitored in the second mass spectrometer (Q3).(Stevens RD, Hillman SL, Worthy S, et al: Assay for free and total carnitine in human plasma using tandem mass spectrometry. Clin Chem 2000;46:727-729)
PDF Report Indicates whether the report includes an additional document with charts, images or other enriched information
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Friday; 8 a.m.