Test Catalog

Test ID: APTSC    
Activated Partial Thromboplastin Time (APTT), Plasma

Method Description Describes how the test is performed and provides a method-specific reference

The activated partial thromboplastin time (APTT) assay is performed on the Instrumentation Laboratory ACL TOP. Patient plasma is combined and incubated with an APTT reagent containing phospholipid, a negatively charged contact factor activator, and buffer. After a specified incubation time, calcium is added to trigger the coagulation process in the mixture. Subsequently, the time to clot formation is measured optically using a wavelength of 671 nm. Mixing studies (see APMSC / APTT Mix 1:1, Plasma) using normal pooled plasma are performed in the Special Coagulation Laboratory on samples with a prolonged APTT, to assist in discriminating between factor deficiency states and coagulation inhibitors, unless further testing is not indicated.(Poller L: Activated partial thromboplastin time [APTT]. In Laboratory Techniques in Thrombosis; A Manual. Edited by J Jesperson, RM Bertina, F Haverkate. Dordrecht and London, Kluwer Academic Publishers, 1999, pp 337-343)

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

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.

2 hours

Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

7 days

Performing Laboratory Location Indicates the location of the laboratory that performs the test