分子诊断测试实验室教育资源 - 赛默飞 | Thermo Fisher Scientific - CN

Foundations of diagnostic testing

This educational series provides a practical, end-to-end overview of laboratory-developed tests (LDTs), in vitro diagnostic (IVD) tests, and the clinical, operational, regulatory, intellectual property, and reimbursement considerations that shape modern diagnostic testing.

The series begins by examining the roles of LDTs and IVDs in molecular diagnostics and contemporary laboratory practice, including emerging bioinformatics and AI-assisted workflows. It then explores how laboratories evaluate, develop, validate, implement, and monitor diagnostic tests through quality management systems and clinical laboratory operations. Subsequent papers address regulatory oversight by accrediting organizations, and intellectual property and reimbursement strategies.

Together, the series offers a roadmap for understanding when to implement a commercial IVD, when to develop an LDT, and how to successfully support diagnostic innovation from concept through clinical adoption.

How do labs implement molecular tests to meet complex clinical needs?

In vitro diagnostic test (IDT)	Laboratory developed test (LDT)
Developed for sale to diagnostic laboratories, health clinics, or consumers Standardized instrument qualification procedures and training required Must be pre-validated with a data analysis and bioinformatics report Must be clinically validated	Developed by individual laboratories; not transferred, licensed, or sold Instrument qualification and training requirements established by individual laboratories Often developed in-house by necessity—no standard assay available Must be clinically verified and can be implemented quickly for emergency use*

IVDs and LDTs are both in vitro diagnostic tests using body fluids (such as blood or urine) or cells/tissues (e.g., pap smear, biopsy) to detect or quantify levels of a desired biomarker. As LDTs and IVDs are both used to diagnose health conditions, it is crucial to understand the differences and advantages.

Advantages of IVDs and LDTs in the lab

IVDs and LDTs both play important roles in modern clinical laboratories. Each offers distinct advantages that help laboratories meet diverse testing needs, improve patient care, and adapt to evolving clinical and operational demands. The following section highlights the key benefits of each approach.

In vitro diagnostic tests (IVD)

Quality system—Tests subject to number of requirements (design controls, manufacturing controls, and handling complaints)
Clinical validity—Helps ensure test detects or measures specified target analyte, or that it is useful for determining presence/absence of clinical condition or predisposition, prior to marketing
Technical support from supplier—To troubleshoot and replace faulty products
Broad distribution—Many laboratories utilizing the test provide data that can increase (or possibly decrease) confidence in the test. Laboratories performing the same IVD test can report proficiency results to confirm the accuracy of the test.
Simplified inventory control—Only order manufactured tests for anticipated use, which reduces the amount of documentation required. Requires less time and effort to maintain in-house IVD inventories.

Laboratory developed test (LDT)

Rapid adaptation—LDTs can be developed and modified relatively quickly to respond to market needs
Control over content—Laboratories can select specific and relevant targets
Lower cost per test—Technological advances and the availability of off-the-shelf bulk reagents have made complex analyses faster and more affordable
Laboratory qualification—The laboratory quality management system (QMS) covers all tests, including LDTs, which is not the case for IVD kit production
Consolidation into a single test—Testing for multiple analytes provides more data per sample and may enable faster diagnosis