11-Dehydro-Thromboxane B2, Urine
Method Description Describes how the test is performed and provides a method-specific reference
Thromboxane B2 (TxB2) is quantitated with an assay developed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Urine specimens are vortexed thoroughly to reconstitute all of the native TxB2. Urine samples are adjusted to a pH of 2.0 + or -0.2 and incubated for 3 hours at ambient temperature to force all the urinary thromboxane into the closed ring form that is recognized by the LC-MS/MS method. After addition of d4 internal standard (d4-11-dTxB2) to the sample, it is positive-pressure filtered and the 11-dTxB2 is separated from the urine matrix via turboflow online extraction. A Cyclone MAX anion-exchange column is used for the extraction, while a Waters Xbridge C8 is used for separation from other prostaglandins. From this column, the sample is transferred to an API 5000 MS/MS for instrumental analysis. A calibration curve is included with each batch of samples. This method does not have any cross-reactivity with the 2,3-dinor thromboxane B2 metabolite.(Lueke AJ, Saenger AK: Development and validation of an LC-MS/MS assay for quantitation of urinary prostaglandins. Clin Chem 2011;57:A133)
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.
Thursday; 8 a.m.
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test