Molecular diagnostics is the branch of medical science that uses laboratory tests to detect, diagnose, and monitor diseases in people. Molecular diagnostics is used to detect disease-causing organisms such as bacteria and viruses, assess their susceptibility to antibiotics or antiviral drugs, monitor therapeutic response, select optimal treatment regimens based on individual patient characteristics including ethnicity and genotype; also it has a major role in cancer screening and prognosis.
The global molecular diagnostics market was valued at USD XX billion in 2016. It is expected to reach USD XX billion by 2026 with a CAGR (compound annual growth rate) of XX% during the forecast period from 2017–2026.
Molecular diagnostics is a process of testing DNA, RNA or proteins in a biological sample to detect the presence of disease-causing agents. These tests are used for diagnosis and monitoring of diseases such as cancer, infectious diseases and inherited disorders. Molecular tests can be performed on both cell-free circulating nucleic acid (cfNA) from patient blood samples or tissue biopsies or obtained from fixed paraffin embedded tissues.
The molecular diagnostics market is segmented into product and service. The product can be further classified into reagent kits, probes & primers, kits & instruments, and others.
The services segment includes service provider and support services. The key players in this market are Abbott Laboratories (U.S.), Qiagen N.V., bioMérieux SA (France), Thermo Fisher Scientific Inc., Illumina Inc., Roche Holding AG (Switzerland) and Danaher Corporation (U.S.).
Reagents and consumables are used for the detection of biomarkers, genetic mutations, infectious diseases and cancer. They make up a large part of the total spending on molecular diagnostics.
Instruments are used to detect the presence of a specific gene or protein in a sample. The detection of DNA is also called genotyping, while the detection of RNA is called RNA expression profiling. In addition, instruments can be used to detect other biomolecules such as antibodies and microRNA molecules.
You might be wondering, “What is software and services?” Well, it's an important part of the molecular diagnostics market. Software helps with managing data, running tests and analyzing results. Services include consulting and training in addition to more traditional products such as laboratory equipment and reagents (which we'll discuss in more detail later).
Molecular Diagnostics Market, By Technology
The molecular diagnostic technologies are broadly categorized into two types: Nucleic Acid-based and Non-Nucleic Acid-based. The nucleic acid-based tests include PCR, RT-PCR, in situ hybridization (ISH), DNA microarray and other methods. The non-nucleic acid based method includes Flow Cytometry etc. These methods are used to identify specific genetic changes in cells or tissues (DNA or RNA) that may be associated with disease or infection.
PCR is a technique to amplify specific DNA sequences, which are then detected by other methods such as gel electrophoresis and electroimmunodiffusion. PCR is used in clinical laboratories to detect mutations responsible for genetic disorders, as well as for other applications such as determining paternity and identifying infectious microorganisms.
In situ hybridization (ISH) is a specialized form of polymerase chain reaction (PCR) that uses fluorescently labeled DNA probes to detect specific nucleic acids in cells, tissues or other biological materials. ISH uses special dyes to bind to the target DNA, which are then detected by fluorescence microscopy or flow cytometry. Although there are many variations on this technique, they all rely on molecular hybridization between a labeled probe and its target sequence of DNA or RNA.
The advantages of ISH include: * Sensitivity - Detection can be made with as few as one copy of the target sequence present in a cell sample; * Specificity - This is essential for differentiating between normal and abnormal cells; * Fast results - Results can be obtained within hours instead of days when using PCR; * Flexibility - Different types of probes may be used during a single experiment without affecting performance
Microarrays are a collection of microscopic spots of DNA attached to a solid surface. The DNA spots can be arranged in any pattern, such as lines, grids or circles. Microarrays are used in molecular diagnostics to detect specific genes or mutations in DNA. The most common type of microarray is called a DNA chip and consists of thousands or millions of microscopic spots where each spot contains one gene.
A microarray may also contain control spots that act as reference points for measuring the expression level of other genes on the array. For example: If you want to know how much your gene changes with respect to another gene, then compare it with an internal control (control) which should not change if your gene does not change its expression level (expression).
DNA sequencing is the process of determining the order of DNA base pairs within a given DNA molecule. The advent of fast and inexpensive sequencing technology has transformed biology, providing more data at faster rates than ever before possible.
Applications for DNA sequencing include:
In clinical applications, researchers use NGS to determine patterns in genes that may indicate disease or abnormal conditions. In research applications, scientists use NGS to determine how various organisms are related to each other on a genomic level; this information can be used as a tool for evolutionary studies as well as provide insight into how diseases develop over time within populations
Transcription-Mediated Amplification (TMA) is a real-time PCR method that uses transcription to amplify nucleic acids in vitro. It is based on the principle of reverse transcription, in which RNA transcribed from cDNA template is used as a primer for DNA synthesis by reverse transcriptase (RT). The resulting cDNA:RNA amplicon can then be amplified by PCR and detected with fluorescent probes.
Other technologies include:
The molecular diagnostic market is growing at a fast rate and is expected to cross USD 33 Billion by 2025. The increasing demand for molecular diagnostics in developing countries, rising incidence of infectious diseases and increasing government initiatives to improve healthcare infrastructure are some of the key factors driving growth in this market. However, high cost of technology, lack of skilled workforce and complexity involved in the test design process are some of the key challenges faced by this market.