Greetings Steemians some, few weeks ago I've been talking on the how we can diagnose diseases based on the cell membrane, and we also gave the methods used in the diagnosis, now we are going to give the diagnosis of diseases at the molecular level. This will be a general introduction.
Designed on Canva
Molecular diagnosis is the identification of etiologic agents of disease at the DNA, RNA, or protein level. Accurate and timely diagnosis of infectious diseases is essential for appropriate medical management of patients. Rapid detection of the microbial pathogen also allows healthcare providers to institute appropriate measures to interrupt transmission to the vulnerable population in the hospital or community.
In the past, diagnoses of infectious diseases were usually linked to the isolation of the infectious agent by culture technique. Although this approach seemed adequate to identify the majority of common infections, it was not reliable for the detection of organisms that were difficult to grow in vitro, had a long incubation period, or could only be visualized by electron microscopy, which is costly and requires specialized personnel to maneuver.
Source An example of electron microscope
In fact, in many cases, the patient was cured long before laboratory results were available. Because of these problems, there is a strong demand for alternative techniques that allow direct detection of infectious agents in clinical samples. Rapid antigen detection tests, such as latex agglutination, enzyme immunoassay (EIA), and direct and indirect immunofluorescence assays, have been developed and, although generally reliable, have a number of limitations.
These include limited sensitivity when organisms are not prevalent or do not shed large amounts of antigen in infected tissues and the need for the antigen to react rapidly with the antibody being tested. For these reasons, there is an interest and demand for new methods of diagnosing infectious disease pathogens. In the 1990s, molecular techniques, including DNA probes and the polymerase chain reaction (PCR), were introduced into clinical microbiology laboratories.
Detection of nucleic acids by hybridization and amplification technologies opened a new period of innovation for microbial diagnosis. After the first report on the application of polymerase chain reaction (PCR) to the clinical diagnosis of human immunodeficiency virus (HIV), several other infectious organisms were detected by the same technique and its variations.
Today, molecular techniques are commonly used to detect an increasing number of organisms. For example, DNA probes are now routinely used to confirm the culture of mycobacteria and have replaced laborious and time-consuming protocols such as hyphal conversion to yeast or exo-antigen extraction for the diagnosis of dimorphic fungi.
This was a general introduction. On our next post we are going to see the traditional methods in the diagnosis of diseases.