View in Browser
New Test: High Sensitivity Troponin I
The Department of Pathology & Laboratory Medicine is pleased to offer the Beckman Access high sensitivity troponin I assay (TPIHS) to replace the current troponin I assay (TPI). High sensitivity troponin assays allow better discrimination of small differences in troponin I values between serial measurements and allow for the establishment of distinct 99th percentile upper reference limits (URL) for males and females. The new assay demonstrates imprecision of < 10% coefficient of variation at the 99th percentile URL and < 1 ng/L standard deviation at the limit of quantitation (6 ng/L). In accordance with current recommendations1, 2, results will be reported in units of ng/L and flagged as elevated based on sex-specific 99th percentile URL established by the manufacturer.

99th percentile reference limits:
Current troponin I (TPI) Access high sensitivity troponin I (TPIHS)
Males < 0.03 ng/mL ≤ 20 ng/L
Females < 0.03 ng/mL ≤ 15 ng/L

Troponin I results differ between methods due to selection of traceability and differences in performance characteristics. Do not use results or cutoffs between different methods interchangeably. Alkaline phosphatase levels above 400 U/L may cause falsely elevated results. Do not use this assay for patients taking asfotase alfa (Strensiq). Human anti-animal antibodies and other interferences may produce unreliable results. Often, in the presence of interfering substances, troponin values may not change accordingly with time. Contact the laboratory if troponin values are inconsistent with the clinical situation and/or interference is suspected.

Effective date: Dec. 4, 2019

Test code: TPIHS

Test methodology: Two-site immunoassay

Turnaround time (TAT):
STAT: 60 minutes
Routine: 2 - 4 hours
Set Up Days: Daily

Specimen requirements:
Collect: 4.0 mL blood in a light green (lithium heparin) tube.
Prepare: Spin down and separate plasma from cells within 2 hours of sample collection. Specimen required: 1.0 mL plasma
Minimum volume: 0.5 mL plasma

Specimen Stability:
(Collection to initiation of testing) after separation from cells:
Ambient: 4 hours
Refrigerated: 48 hours
Frozen: 180 days; thaw only once

Rejection criteria:
Specimens that exceed stated stability, unlabeled/mislabeled/mismatched specimens, specimens submitted in leaking containers, grossly hemolyzed or lipemic specimens

References available here

A summary of all tests offered by our laboratory services can be found here:


Bridgit O. Crews, PhD, DABCC
Clinical Chemistry & Toxicology

Edwin S. Monuki, MD, PhD
Department of Pathology & Laboratory Medicine
© 2019 The Regents of the University of California. All rights reserved. Proprietary and Confidential. For Internal Distribution Only.