Biomarker Lens

Common biomarkers

  • Hemoglobin
  • Glucose
  • ALT
  • Apolipoprotein B
  • C-Reactive Protein, Cardiac
  • Ferritin
  • Alb/Creat Ratio, Urine
  • Alkaline Phosphatase
  • FSH
  • T4,Free(Direct)

Biomarkers · Chemical

PTT-LA

Primary unit
sec
LOINC codes
34571-0
Tests that measure PTT-LA
Labcorp 6, Quest Diagnostics 3

Ranges

Each lab publishes a reference range for the population groups it tests, usually the middle 95% of results. These intervals describe that population, not an optimal or healthy target. How ranges differ

Quest Diagnostics, Lupus Anticoagulant Evaluation with Reflex 7079

PopulationInterval
Lupus AnticoagulantNot detected
PTT-LA Screen≤40 sec
dRVVT Screen≤45 sec

Quest Diagnostics test catalog, 7079

Tests

Check the catalog code, specimen, method and preparation for every test that measures PTT-LA. Select up to five tests to compare them side by side.

Labcorp 6 tests

Panels that include this biomarker

  • Lupus Anticoagulant With Reflex 117892

    2 analytes · Plasma · Fasting not stated · Turnaround 2 - 3 days

    Method and collection
    Method
    PTT-LA (lupus-sensitive aPTT) and dRVVT screen; mixing study if screening tests are prolonged; confirmation if the mixing studies do not correct
    Preparation
    Ideally, the patient should not be on anticoagulant therapy. Avoid warfarin (Coumadin®) therapy for two weeks prior to the test and heparin, direct Xa, and thrombin inhibitor therapies for about three days prior to testing.
    Collection
    Citrated plasma samples should be collected by double centrifugation. Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate.19 Evacuated collection tubes must be filled to completion to ensure a proper blood to anticoagulant ratio.20,21 The sample should be mixed immediately by gentle inversion at least six times to ensure adequate mixing of the anticoagulant with the blood. A discard tube is not required prior to collection of coagulation samples unless the sample is collected using a winged (butterfly) collection system. With a winged blood collection set a discard tube should be drawn first to account for the dead space of the tubing and prevent under-filling of the evacuated tube.22,23 When non-citrate tubes are collected for other tests, collect sterile and nonadditive (red-top) tubes prior to citrate (blue-top) tubes. Any tube containing an alternate anticoagulant should be collected after the blue-top tube. Gel-barrier tubes and serum tubes with clot initiators should also be collected after the citrate tubes. Centrifuge for 10 minutes and carefully remove 2/3 of the plasma using a plastic transfer pipette, being careful not to disturb the cells. Deliver to a plastic transport tube, cap, and re-centrifuge for 10 minutes. Use a second plastic pipette to remove the plasma, staying clear of the platelets at the bottom of the tube. Transfer the plasma into a Labcorp PP transpak frozen purple tube with screw cap (Labcorp No. 49482). Freeze immediately and maintain frozen until tested. Please print and use the Volume Guide for Coagulation Testing to ensure proper draw volume.
    Labcorp catalog page
  • Prolonged Activated Partial Thromboplastin Time (aPTT) 117796

    6 analytes · Plasma · Fasting not stated · Turnaround 2 - 3 days

    Method and collection
    Method
    See individual tests.
    Preparation
    Avoid warfarin (Coumadin®) therapy for two weeks and heparin therapy for two days prior to the test.
    Collection
    Citrated plasma samples should be collected by double centrifugation. Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate.1 Evacuated collection tubes must be filled to completion to ensure a proper blood to anticoagulant ratio.2,3 The sample should be mixed immediately by gentle inversion at least six times to ensure adequate mixing of the anticoagulant with the blood. A discard tube is not required prior to collection of coagulation samples, except when using a winged blood collection device (ie, "butterfly"), in which case a discard tube should be used.4,5 When noncitrate tubes are collected for other tests, collect sterile and nonadditive (red-top) tubes prior to citrate (blue-top) tubes. Any tube containing an alternate anticoagulant should be collected after the blue-top tube. Gel-barrier tubes and serum tubes with clot initiators should also be collected after the citrate tubes. Centrifuge for 10 minutes and carefully remove 2/3 of the plasma using a plastic transfer pipette, being careful not to disturb the cells. Deliver to a plastic transport tube, cap, and recentrifuge for 10 minutes. Use a second plastic pipette to remove the plasma, staying clear of the platelets at the bottom of the tube. Transfer the plasma into a Labcorp PP transpak frozen purple tube with screw cap (Labcorp No. 49482). Freeze immediately and maintain frozen until tested. Please print and use the Volume Guide for Coagulation Testing to ensure proper draw volume.
    Labcorp catalog page
  • Thrombotic Risk, Acquired 117145

    11 analytes · Serum · Fasting not stated · Turnaround 3 - 7 days

    Method and collection
    Method
    See individual tests.
    Preparation
    Do not draw from an arm with a heparin lock or heparinized catheter.
    Collection
    Citrated plasma samples should be collected by double centrifugation. Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate.1 Evacuated collection tubes must be filled to completion to ensure a proper blood to anticoagulant ratio.2,3 The sample should be mixed immediately by gentle inversion at least six times to ensure adequate mixing of the anti-coagulant with the blood. A discard tube is not required prior to collection of coagulation samples except when using a winged blood collection device (i.e., "butterfly"), in which case a discard tube should be used.4,5 When non-citrate tubes are collected for other tests, collect sterile and nonadditive (red-top) tubes prior to citrate (blue-top) tubes. Any tube containing an alternate anticoagulant should be collected after the blue-top tube. Gel-barrier tubes and serum tubes with clot initiators should also be collected after the citrate tubes. Centrifuge for 10 minutes and carefully remove 2/3 of the plasma using a plastic transfer pipette, being careful not to disturb the cells. Deliver to a plastic transport tube, cap and recentifuge for 10 minutes. Use a second plastic pipette to remove plasma, staying clear of the platelets at the bottom of the tube. Transfer the plasma into a Labcorp PP transpak frozen purple tube with screw cap (Labcorp No. 49482). Freeze immediately and maintain frozen until tested. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested. It is important to centrifuge blood samples for plasma collection immediately after collection to separate the plasma from the blood cells. If immediate centrifugation is not possible, collected blood specimens should be kept on ice and centrifuged within an hour. Serum: If a red-top tube is used, transfer separate serum to a plastic transport tube. Please print and use the Volume Guide for Coagulation Testing to ensure proper draw volume.
    Labcorp catalog page
  • Antiphospholipid Syndrome (APS) Assessment 164535

    14 analytes · Serum · Fasting not stated · Turnaround 4 - 6 days

    Method and collection
    Method
    Clot-based assays for lupus anticoagulants and enzyme-linked immunoassays (ELISAs) for antiphospholipid antibodies
    Preparation
    Do not draw from an arm with a heparin lock or heparinized catheter.
    Collection
    Plasma: Citrated plasma samples should be collected by double centrifugation. Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate.26 Evacuated collection tubes must be filled to completion to ensure a proper blood-to-anticoagulant ratio.27,28 The sample should be mixed immediately by gentle inversion at least six times to ensure adequate mixing of the anti-coagulant with the blood. A discard tube is not required prior to collection of coagulation samples except when using a winged blood collection device (i.e., "butterfly"), in which case a discard tube should be used.29,30 When noncitrate tubes are collected for other tests, collect sterile and nonadditive (red-top) tubes prior to citrate (blue-top) tubes. Any tube containing an alternate anticoagulant should be collected after the blue-top tube. Gel-barrier tubes and serum tubes with clot initiators should also be collected after the citrate tubes. Centrifuge for 10 minutes and carefully remove 2/3 of the plasma using a plastic transfer pipette, being careful not to disturb the cells. Deliver to a plastic transport tube, cap and recentifuge for 10 minutes. Use a second plastic pipette to remove plasma, staying clear of the platelets at the bottom of the tube. Transfer the plasma into a Labcorp PP transpak frozen purple tube with screw cap (Labcorp No. 49482). Freeze immediately and maintain frozen until tested. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested . It is important to centrifuge blood samples for plasma collection immediately after collection to separate the plasma from the blood cells. If immediate centrifugation is not possible, collected blood specimens should be kept on ice and centrifuged within an hour. Serum: If a red-top tube is used, transfer separate serum to a plastic transport tube. Please print and use the Volume Guide for Coagulation Testing to ensure proper draw volume.
    Labcorp catalog page
  • Thrombotic Risk Assessment 117155

    14 analytes · Serum · Fasting not stated · Turnaround 3 - 7 days

    Method and collection
    Method
    See individual tests.
    Preparation
    Do not draw from an arm with a heparin lock or heparinized catheter.
    Collection
    Citrated plasma samples should be collected by double centrifugation. Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate.1 Evacuated collection tubes must be filled to completion to ensure a proper blood to anticoagulant ratio.2,3 The sample should be mixed immediately by gentle inversion at least six times to ensure adequate mixing of the anti-coagulant with the blood. A discard tube is not required prior to collection of coagulation samples except when using a winged blood collection device (i.e., "butterfly"), in which case a discard tube should be used.4,5 When non-citrate tubes are collected for other tests, collect sterile and nonadditive (red-top) tubes prior to citrate (blue-top) tubes. Any tube containing an alternate anticoagulant should be collected after the blue-top tube. Gel-barrier tubes and serum tubes with clot initiators should also be collected after the citrate tubes. Centrifuge for 10 minutes and carefully remove 2/3 of the plasma using a plastic transfer pipette, being careful not to disturb the cells. Deliver to a plastic transport tube, cap and recentifuge for 10 minutes. Use a second plastic pipette to remove plasma, staying clear of the platelets at the bottom of the tube. Transfer the plasma into a Labcorp PP transpak frozen purple tube with screw cap (Labcorp No. 49482). Freeze immediately and maintain frozen until tested. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested. It is important to centrifuge blood samples for plasma collection immediately after collection to separate the plasma from the blood cells. If immediate centrifugation is not possible, collected blood specimens should be kept on ice and centrifuged within an hour. Serum: If a red-top tube is used, transfer separate serum to a plastic transport tube. Please print and use the Volume Guide for Coagulation Testing to ensure proper draw volume.
    Labcorp catalog page

Quest Diagnostics 3 tests

Single-analyte tests

  • Lupus Anticoagulant Evaluation with Reflex 7079

    Plasma · Fasting not stated · Turnaround Set up: Mon-Sat

    Method and collection
    Method
    Clot detection
    Collection
    Platelet-poor plasma: Centrifuge light blue-top tube for 15 minutes at approximately 1500 g within 60 minutes of collection. Using a plastic pipette, remove plasma, taking care to avoid the WBC/platelet buffy layer and place into a plastic vial. Centrifuge a second time and transfer platelet-poor plasma into a new plastic vial. Plasma must be free of platelets (<10,000/mcL). Freeze immediately and ship on dry ice.
    Quest Diagnostics catalog page
  • PTT-LA with Reflex to Hexagonal Phase Confirmation 17408

    Plasma · Fasting not stated · Turnaround Set up: Mon-Sat

    Method and collection
    Method
    Clot Detection
    Collection
    Please submit a separate, frozen vial for each special coagulation assay ordered. Draw blood in a light blue-top tube containing 3.2% sodium citrate, mix gently by inverting 3-4 times. Centrifuge 15 minutes at 1500 g within one hour of collection. Using a plastic pipette, remove plasma, taking care to avoid the WBC/platelet buffy layer and place into a plastic vial. Centrifuge a second time and transfer platelet-poor plasma into a new plastic vial(s). Freeze immediately and transport on dry ice.
    Reference notes
    ≤40 seconds
    Quest Diagnostics catalog page

Panels that include this biomarker

  • Mixing Study 8922

    3 analytes · Plasma · Fasting not stated

    Method and collection
    Method
    Clot Detection
    Collection
    Please submit a separate, frozen vial for each special coagulation assay ordered. Draw blood in a light blue-top tube containing 3.2% sodium citrate, mix gently by inverting 3-4 times. Centrifuge 15 minutes at 1500 g within one hour of collection. Using a plastic pipette, remove plasma, taking care to avoid the WBC/platelet buffy layer and place into a plastic vial. Centrifuge a second time and transfer platelet-poor plasma into a new plastic vial(s). Freeze immediately and transport on dry ice.
    Reference notes
    Prothrombin Time | 9.0-11.5 sec Immediate PT-Mix | ≤11.5 sec PTT-LA, Baseline | ≤40 sec Immediate PTT-LA Mix | See Laboratory Report Incubated PTT-LA Mix | See Laboratory Report
    Quest Diagnostics catalog page

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Sources

Verify these ranges and sources

We compile this page from named laboratory catalogs, guidelines and studies. Labs calculate reference intervals from the people they test, for one assay method and one population group, so an interval describes that population rather than an optimal target.

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