Recognizing this challenge, Dr Fay Betsou, Director of the Biological Resource Center at the Instut Pasteur, Paris (CRBIP), and colleagues from FIND and Task Force for Global Health have introduced an important new concept that could help transform the development of diagnostics worldwide. Known as the Target Specimen Profile, or TSP, this framework provides a systematic way to define exactly what biological samples are needed to develop, validate, and quality assure diagnostic tests.

The idea may sound technical, but its implications are profound. By helping scientists collect the right specimens from the beginning, TSPs could accelerate the creation of better diagnostics for some of the world’s most challenging infectious diseases.

For decades, diagnostic developers have relied on what are known as Target Product Profiles. These documents describe what a diagnostic test should ultimately achieve. They define desired levels of sensitivity and specificity, identify the intended users, and clarify how and where the test will be used. Target Product Profiles help guide companies and researchers toward creating products that meet public health needs.

Yet there has long been a gap between defining the desired product and obtaining the biological materials needed to prove that the product works. Developing a test requires carefully characterized samples from patients with and without disease. Validation requires even larger collections of specimens representing different populations, disease clinical stages, and geographic regions. Quality control programs require additional materials to ensure that tests continue performing reliably over time.

This is where the Target Specimen Profile enters the picture. A TSP serves as a blueprint for the biological specimens needed throughout the life cycle of a diagnostic test. It specifies the types of samples required and the clinical information that should accompany them, the number of donors needed, the geographical diversity required, and the laboratory characteristics that make the specimens fit for purpose.

In essence, a TSP answers a deceptively simple question: if we want a diagnostic test that works in the real world, what samples do we need to collect today? Dr Fay Betsou describes the TSP as a tool that can guide biobanks in building collections that truly support diagnostic innovation. Rather than gathering samples opportunistically, organizations can collect specimens according to carefully defined requirements that anticipate future scientific needs.

The concept emerges at a critical moment. Public health systems continue to face threats from neglected tropical diseases, emerging pathogens, and outbreaks with pandemic potential. Developing effective diagnostics for these conditions often depends on access to rare and difficult-to-obtain biological materials. In many cases, researchers struggle to locate suitable specimens, delaying development efforts and increasing costs.

The TSP framework seeks to address this challenge by creating a common language between diagnostic developers and biobanks. Instead of searching for any available samples that can be found here or there, researchers can work from predefined specimen requirements.

To demonstrate the concept, the authors developed ten illustrative TSP reports covering a range of infectious diseases. These examples include human African trypanosomiasis, cutaneous and visceral leishmaniasis, leprosy, lymphatic filariasis, onchocerciasis, schistosomiasis, soil-transmitted helminthiasis, trachoma, Nipah virus disease, and Lassa fever.

Together, these examples reveal the remarkable complexity involved in assembling specimen collections capable of supporting diagnostic development. Consider schistosomiasis, a parasitic disease that affects millions of people worldwide. At first glance, one might assume that obtaining samples from infected individuals would be sufficient. The TSP demonstrates that the reality is far more complicated.

Different types of specimens may be needed depending on the diagnostic approach. Researchers may require serum, plasma, urine, stool samples, or dried blood spots. Important clinical annotations must accompany these specimens, including detailed laboratory findings that confirm infection status. Samples may need to come from multiple geographic regions because parasite strains vary across continents. Validation studies must also include carefully selected negative controls and samples from patients with other infections that could produce misleading results.

The schistosomiasis TSP even addresses practical factors that many people never consider. The timing of sample collection, the temperature at which specimens are processed, storage conditions, and the number of freeze-thaw cycles can all influence diagnostic performance. A specimen is more than a tube of biological material. It is a scientific resource whose value depends heavily on how it was collected, handled, and documented.

This level of detail helps ensure that diagnostic tests are reliably evaluated. It also reduces the risk that promising biomarkers will fail during later stages of development because the original specimens were not sufficiently representative.

Another revealing example comes from the TSP for Lassa fever, a viral disease found primarily in West Africa. The report highlights the importance of collecting specimens from different endemic regions because the virus exhibits substantial genetic variation. Antibodies produced in response to one strain may differ from those associated with another strain. If diagnostic developers rely on specimens from only a single location, they risk creating tests that perform inconsistently across affected regions.

This illustrates one of the central insights behind the TSP concept. Diseases are not uniform. Pathogens evolve. Human populations differ. Environmental conditions vary. Diagnostic tests must account for this complexity if they are to succeed.

The same principle applies to many other diseases covered by the TSP reports. For onchocerciasis, different specimen types may be needed depending on whether a program is mapping disease prevalence or deciding when mass drug administration can safely stop. For leishmaniasis, specimen requirements vary according to disease manifestations and anatomical sites. For lymphatic filariasis, defining positivity requires careful attention to evidence of live worms rather than relying solely on indirect indicators.

Each disease presents unique challenges. Each requires a carefully tailored specimen strategy. Beyond supporting diagnostic development, TSPs also contribute to quality assurance. Once a test reaches the field, laboratories need reference materials and external quality assessment programs to maintain consistent performance. The same specimen types that support validation can often contribute to these critical quality systems.

This broader perspective represents one of the strengths of the framework. Rather than viewing specimens as resources needed only during development, TSPs recognize their continuing importance throughout the diagnostic lifecycle.

The approach also highlights the increasingly important role of biobanks. Modern biobanks are far more than storage facilities. They are sophisticated scientific infrastructures that manage biological resources, clinical data, ethical requirements, and quality systems. By following TSP guidance, biobanks can create collections that are more valuable to researchers and more responsive to global health priorities.

Importantly, the authors emphasize that TSPs are designed to be product agnostic and company agnostic. The goal is not to support a particular manufacturer or technology. Instead, the profiles describe specimen collections large and diverse enough to meet the needs of any developer working in a given disease area. This neutrality is essential. It allows biobanks to serve the broader scientific community while helping ensure that specimens collected today remain useful as technologies evolve.

The concept may also extend far beyond infectious diseases. Although the initial reports focus on infections, the authors note that TSPs could be adapted for fields such as oncology. In cancer research, specimen profiles should incorporate tumour classifications, molecular subtypes, and pathological staging information. Similar adaptations could support diagnostics in many other areas of medicine.

In this sense, the TSP framework represents more than a tool for infectious disease research. It offers a new way of thinking about biological resources and their relationship to innovation.

Of course, implementing these ambitious specimen collections will not be easy. The ideal panels described in many TSP reports require substantial investment. Collecting samples from diverse populations, documenting them thoroughly, storing them appropriately, and maintaining long-term access all demand resources and expertise.

These challenges are especially significant in low and middle income countries, where many of the targeted diseases are most prevalent. The authors acknowledge that financial support will be necessary if biobanks in these regions are to build and sustain the collections envisioned by the TSP framework.

Yet the potential benefits are considerable. Diagnostic failures are costly. Biomarkers that appear promising but later prove unsuitable consume valuable time and funding. Delays in diagnostic development can hinder disease control efforts and leave vulnerable populations without effective tools.

By improving specimen quality and availability, TSPs could reduce these inefficiencies. Better specimens lead to better validation. Better validation leads to more reliable diagnostics. More reliable diagnostics support better patient care and stronger public health programs.

The significance of this contribution lies in a new form of scientific planning. It recognizes that successful diagnostics begin long before a test reaches the laboratory bench. They begin with thoughtful preparation, careful collection, and rigorous characterization of the biological materials on which all diagnostic science depends.

Dr Fay Betsou and her colleagues have drawn attention to a foundational element of medical innovation that often remains hidden from public view. Their work reminds us that progress in healthcare depends on the quality of the resources that support discovery.

As emerging diseases continue to challenge global health systems and neglected tropical diseases remain a burden for millions of people, the need for robust diagnostics will only grow. The Target Specimen Profile offers a practical roadmap for ensuring that researchers have the specimens they need to meet this challenge.