What is Cell-based Diagnostics?

Cell-based diagnostics rely on the evaluation of whole cells to detect the presence of disease. Cell-based assays are the gold standard for detection of the majority of infectious organisms. However, cell-based diagnostics generally require sophisticated laboratory facilities and highly skilled personnel that are not practical for use in low resources settings.

Overview

Cell-based diagnostics include a wide range of standard laboratory techniques, such as growth, visualization, and qualitative evaluation of whole cells, to detect disease. Examples of cell-based diagnostic approaches are summarized in the table below.

  Description Strengths Weaknesses
Culture Host cells or infectious organisms are grown from patient samples in the laboratory Growth in culture allows detection of low-level infections through amplification Cells or organisms grown must then be visualized or detected, requires sterile laboratory conditions
Microscopy Host cells or infectious organisms are visualized directly in the patient sample Visual detection of disease Requires microscope, requires highly skilled technician, lack of amplification reduces sensitivity
Plaque assays Indirectly measures presence of infectious organism by applying patients samples to healthy host cells in culture and looking for damage Detection of low-level infections through amplification, quantitative Requires highly skilled technician, requires sterile laboratory conditions
Xenodiagnosis Patient sample is used to inoculate a laboratory animal for amplification of infection Growth in laboratory animal allows detection of low-level infections through amplification Cells or organisms grown in the laboratory animal must then be visualized or detected, requires sterile laboratory conditions, required maintenance of laboratory animals
Flow cytometry Host cells or infectious organisms are directly or indirectly (using dyes or markers) counted to assess the presence of disease Quantitative and sensitive Requires expensive equipment, requires highly skilled technician

Existing Products

Cell-based diagnostics are applicable to nearly every human condition. As these diagnostics rely on standard laboratory techniques, their successful application is more highly dependent on the skill level of the technician performing the assay than the nature of the disease being diagnosed.

Cell-based Diagnostics for Non-Neglected Tropical Diseases

Evaluation of patient cells by microscopy can be used to detect the presence of cancer, autoimmune diseases, infections, and a variety of other conditions. In the case of cancer, tumor biopsies are preserved, stained, and visually examined by a trained pathologist. Flow cytometry is often used in conjunction with microscopy to characterize the cancer in more detail. For instance, flow cytometry can be used to identify cells expressing specific markers of disease that provide clues as to disease severity, patient prognosis, or optimal treatment.

Cell-based Diagnostics for Neglected Tropical Diseases

Cell-based diagnostics are available for most neglected diseases. However, as many of these diseases affect poor and marginalized populations without access to hospitals, centralized laboratories, or other infrastructure required for cell-based diagnosis, these techniques are rarely employed in the developing world.

Cell-based Diagnostic Technique Disease Description
Culture Tuberculosis Patient sputum sample cultured in nutrient rich broth and then visualized by microscopy to detect presence of infection. By adding tuberculosis treatments to the culture media, tuberculosis drug resistance can also be assessed.
Microscopy Schistosomiasis, soil-transmitted helminthes, fascioliasis Patient stool samples are examined by microscopy to look for the presence of eggs.
Plaque assays Dengue Patient blood samples are diluted and applied to cultured cells. Cells are monitored for damage to quantify the level of viral infection.
Xenodiagnosis Chagas disease Laboratory reared, uninfected insect allowed to bite patient. Insect is killed and examined for the presence of parasites.
Flow cytometry HIV CD4 positive T-cells are counted to monitor progression of diseases and treatment efficacy.

Get Involved

To learn how you can get involved in neglected disease drug, vaccine or diagnostic research and development, or to provide updates, changes, or corrections to the Global Health Primer website, please view our FAQs.

Pipline

Analysis

Cell-based diagnostic assays are available for a variety of neglected tropical diseases. However, as many of these assays require sophisticated equipment or technician training, they are difficult to employ in field settings. The majority of cell-based diagnostics in development for neglected tropical diseases are simplified techniques or assays, such as simplified microscopes, microscopes with cellphone interfaces to allow for remote evaluation of images, or simplified flow cytometers that can be used in low resource settings.

Get Involved

To learn how you can get involved in neglected disease drug, vaccine or diagnostic research and development, or to provide updates, changes, or corrections to the Global Health Primer website, please view our FAQs.

There are numerous publications and manuals with detailed protocols and explanations of the principles of cell-based assays and standard laboratory microbiology practices.

More information on use of cell-based assays for diagnosis of specific neglected diseases is available in each of the specific disease profiles.

Get Involved

To learn how you can get involved in neglected disease drug, vaccine or diagnostic research and development, or to provide updates, changes, or corrections to the Global Health Primer website, please view our FAQs.