Diagnostics

Overview

Diagnostics are able to quickly provide highly accurate and very specific information, which is essential in detecting diseases rapidly. Such diseases can be cancer, infections or toxins, but the list goes on.

Conventional Diagnostic Methods

  • Conventional diagnostic usually detects pathogens at a particular stage of its life cycle.

  • Identify pathogens based on their phenotypic characteristics, e.g. cytopathic effects in tissue cultures.

  • Identify pathogens (parasites/fungi) through microscope.

  • Reliable but time-consuming.

  • Due to different variant and variation in pathogen’s life cycle, each stage may require different tests.

General Steps for Conventional Diagnostics Methods

  1. Macroscopic & microscopic identification which involves staining procedure (used to understand its morphology).

  2. Microbiological identification which involves growing pathogens in media (used to study its life cycle).

  3. Differentiation of pathogens based on characteristics.

  4. Antibody binding ability which involves the use of immunological assay (used to identify the type of antibody that be bounded to the pathogen.

Why Is There A Need To Improve the Conventional Diagnostic Methods?

  • Emergence of new pathogens (Zika Virus, H1N1 Virus, COVID-19)

  • Emergence of multiple variants within a short timespan

  • Bioterrorism (speed of diagnostics to quickly isolated people who are affected)

Synthetic Biology Enabled Diagnostic Methods

  • Nucleic acid-based diagnostics which detects specific DNA or RNA sequences in the pathogen.

  • Can be used as a point-of-care service to rapidly detect infected people.

  • Specific primers or probes to be used in detection.

General Steps for Synthetic Biology Enabled Diagnostics Methods

  1. Identification of genome

  2. Design of primer and DNA/RNA probe

  3. Amplification of target sequence

  4. Quantification of pathogen via fluorescence/other detection methods

Examples of Synthetic Biology Enabled Diagnostic Methods

  • Real-time RT-PCR kits that are used for rapid detection of methicillin resistant S.aureus

  • Flu SC2 Multiplex Assay (First COVID-19 diagnostic assay)

  • 67 approved COVID-19 PCR based molecular test

  • Generation of chimeric antigens that are specific to a disease status or pathogens in serum-based diagnostic assays

  • DNA origami nanostructures used as malaria or heart failure diagnostic tools.