Introduction to Nucleic Acids and Application to Infectious Disease Detection
By Joan Polancic, MSEd, CLS(NCA)
American Society for Clinical Laboratory Science
Advances in technology in the last 30 years have driven changes and advancements in how the hospital clinical or medical laboratory analyzes specimens to provide useful data to physicians for patient diagnosis, monitoring or treatment of disease states or disorders. Prior to the 1970’s most tests that a physician ordered on his or her patients were analyzed in the hospital clinical laboratory using manual methods – which involved careful pipetting of reagents and patient samples, mixing in test tubes and using a spectrophotometer to measure; performing blood cell counts using a specially designed slide (hemacytometer) and microscope; or streaking specimens for culture growth and performing a number of biochemical tests manually on the organism to determine its identity.
In the 1970’s automated testing for analysis of blood samples (e.g. glucose, cholesterol) was introduced that allowed the clinical laboratorian to perform more tests more quickly. In the 1980’s enzyme immunoassay allowed the introduction of more efficient testing methods for hormones, drugs of abuse, and therapeutic drug monitoring.
In the late 1980’s and 1990’s further miniaturization of electronics brought the advance of “Point of Care” technology that increased testing at the patient’s bedside or in the physician’s office. The advancing technology of today is DNA or Molecular Technology. Molecular technology is at the threshold of many possibilities for use in the clinical or hospital laboratory. Currently, molecular technology is used to identify disease causing organisms, genetic disorders or tumors.
The purpose of this learning unit is to introduce the basics of nucleic acids so that current molecular technologies can be understood. Here are the learning goals for this unit:
- Explain the components and basic structure of DNA & RNA
- Discuss the roles of DNA & RNA’s in protein synthesis
- Discuss the principle of the hybridization probe assay
First you will learn about DNA & RNA and their role in the cell. Then one principle of a molecular test will be presented to illustrate how this new technology is used to identify some infectious organisms.