Test ID: TXBU
11-Dehydro-Thromboxane B2, Urine
Method Description
Describes how the test is performed and provides a method-specific reference
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 +/-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.


