Have you ever gotten a cut after falling off your bike? OUCH! The cut may cause some pain initially, but it heals entirely within a few days. Biology can explain this! Biological tests can prove biological concepts like healing.
These tests provide us with information on the fantastic processes going on inside the body. Clinical tests like EKGs and EEGS that measure the body's physical health are done in a hospital setting and allow doctors to understand the patient's body. So, let's dive into the different types of biological tests!
- First, we will look at an overview of types of biological tests.
- Then, we will learn about biological testing for sterilizers.
- After, we will talk about the importance of different biological tests.
- Lastly, we will explore molecular biological testing.
Types of Biological Tests Overview
Let's start our journey by doing an overview of biological tests. Biological tests are used to assess substance use, bodily health, viral and bacterial contamination, and even tumor growth!
Biological tests are standardized procedures used to assess the health, function, and contamination of a biological organism.
Drug Tests
They are many biological tests/assays that can be used to provide insight into a person's health.
For example, a common test used to assess if someone is using controlled substances is a drug test.
Typical drug tests assess a person's use of marijuana, cocaine, amphetamines, and opioids.
There are many types of drug tests, but the most common type is a urine-based drug test. During a urine-based drug test, urine tests may be conducted as part of employment protocols if a person is a pilot, a doctor, or has any job that is affiliated with managing people.
Urine test results showcase the presence of drug metabolites in a person's urine. These metabolites are present in a person's system after the effects of the drug have worn out and are byproducts of your body metabolizing the drug.
Electrocardiogram (EKG)
Another type of biological test is an electrocardiogram, also known as an EKG.
An electrocardiogram (EKG) test is typically administered in a hospital setting and serves to record signals from the heart to assess the heart's function.
During an EKG, electrodes are placed on a person's chest to record the heart's electrical signals that make the heartbeat. These signals show up as waves on an attached computer monitor, and the healthcare provider can read these waves to see if there is improper signaling within the heart.
- An EKG can be used to assess irregular heart rhythms or blocked or narrowed arteries.
Electroencephalogram (EEG)
Other hospital bases biological tests include prostate exams, pelvic exams, electroencephalograms (EEG), and much more. Prostate exams assess the reproductive health of males, while pelvic exams assess the reproductive health of females. These types of tests are also used to screen for prostate cancer and ovarian cancer, respectively.
Now, let's talk about EEGs.
Electroencephalograms (EEGs) are used to measure the electrical activity in the brain via small electrodes that are placed on a person's scalp.
In your body, your neurons, which are the cells in your brain, transmit electrical signals to all areas of your body, telling your body to keep working or to stop working. Neurological signals tell your heart to beat, tell your muscle to move, and even transmit sensory signals from the world around you to your brain for processing.
EEGs measure the quality and quantity of nerve signals in your brain and can alert neurologists of possible nerve damage.
- EEGs are used for people with neurological diseases such as Alzheimer's Disease, Parkinson's Disease, and Huntington's Disease.
Biological Testing for Sterilizers
Biological tests are also commonly used to measure the sterility of a room or of an object. These types of biological tests are commonly done in hospitals and in labs when the sterility of equipment needs to be pristine.
In hospitals, surgical equipment such as scalpels needs to be 100% sterile before it can be used on another patient. An autoclave often sterilizes surgical tools and lab equipment.
An autoclave is a machine used for the sterilization of lab and medical equipment.
A typical test used to assess and monitor sterility is the spore test. The spore test assesses the sterilization process directly by killing highly resistant microorganisms such as bacteria. Usually, tools are cleaned via UV light or anti-spore spray.
Since spore tests are not done every day, the sterility of equipment must be mechanically and chemically tested to assess sterility.
- Mechanical tests/monitoring involves checking the gauges for pressure and temperature and how long the tools have been in the autoclave.
- Chemical monitoring/testing of sterility involves the use of sensitive chemicals that change color when exposed to high temperatures. During an autoclave cycle, you can place chemical indicator tapes, strips, or tabs in the machine, and after the cycle, you can check the color or the strip to assess if the instruments are completely sterilized!
Importance of Different Biological Tests
Biological tests are extremely important because they provide insight into what is going on inside the body. Before biological tests were invented, it was hard for medical professionals to diagnose diseases which made it hard to treat these diseases.
The development of good biological tests has paved the way for modern medicine and the development of quality treatment methods. For instance, without biological tests, it would have been hard for scientists to identify the root cause behind COVID-19 when it first emerged. Without identifying the cause of COVID-19, we would not have been able to develop treatments or vaccines against it!
Biological tests are also important because they help us evolve as society becomes more advanced. Prior to medications, having an infected cut was an almost guaranteed death sentence since there were no antibiotics at the time.
In the 21st century, we are constantly getting into car accidents, boating accidents, and sports accidents, where we are frequently hurt and exposed to infectious agents. Now that antibiotics have been around for almost a century, getting a small cut or wound is considered a simple accident that has an extremely low mortality rate!
The creator of the first antibiotic medication did many biological tests before successfully discovering his drug, penicillin. Biological tests are what make modern medicine what it is today!
Did you know that the antibiotic penicillin comes from the fungus Penicillium chrysogenum? To learn more about fungi, check out "Fungi"!
Molecular Biological Testing
The detection of bacterial and viral infections in the body can be done using molecular biological tests. These tests can be used to detect if a person has HIV, SARS-COV-2, influenza, staphylococcus infections, and many other pathogens!
A common molecular biological test used to detect the presence of bacterial or viral infections is a polymerase chain reaction, also known as PCR.
The polymerase chain reaction (PCR) technique targets a specific segment of a DNA molecule and amplifies it (copies it in quantity).
There are three steps involved in a polymerase chain reaction (PCR):
Denaturation
Annealing
Extension
During denaturation, the sample is heated to 96 °C, allowing the DNA strands to separate into two template strands. During annealing, the sample is cooled to 55 °C to allow the primers to bind to the template strands.
Primers are short, single-stranded DNA strands composed of sequences that are complementary to sequences at each end of the target sequence.
After, in the extension step, the sample is heated to 72 °C, allowing DNA polymerase to synthesize complete complementary DNA strands, starting from the end of each primer.
DNA polymerase is an enzyme that synthesizes DNA from nucleotides.
Let's look at an example!
During a COVID-19 test, a person's nose is swabbed, and the cells collected during the swab are placed into media that keep the cells from dying (figure 3). The patient sample is then transported to a molecular biology lab, where the PCR test is performed.
During PCR, RNA is extracted from the sample and undergoes a reaction known as reverse transcription. During reverse transcription, RNA is reverse transcribed into cDNA, which is complementary to the RNA sequence.
These cDNA sequences are then placed into an incubator along with forward and reverse primers specific to the SARS-COV-2 virus that amplify the cDNA over and over again until these sequences can be measured. If SARS-COV-2 is present in the patient's sample, then it will show up on the PCR analysis!
PCR is based on DNA replication, the process by which our cells duplicate their genetic material before dividing.
Now, let's explore the different biological tests used to detect the human immunodeficiency virus (HIV), which is the virus that causes AIDS. These are:
Antibody tests look for antibodies to the HIV virus in a person's blood or saliva.
Antigen/antibody tests assess the presence of both HIV antibodies and antigens.
Nucleic acid tests like PCR detect the presence of the actual HIV virus in patient cells.
An antibody is a specialized protein that is created in response to a specific virus antigen that protects healthy cells from being infected by the virus again.
An antigen is a specific protein that is only found on a particular pathogen.
There are many molecular biology tests available that test for many pathogenic infections and each of them is important in the field of healthcare!
Types of Biological Tests - Key takeaways
- A common test used to assess if someone is using controlled substances is a drug test.
- During an EKG, electrodes are placed on a person's chest to record the heart's electrical signals that make the heartbeat.
- Prostate exams assess the reproductive health of males while pelvic exams assess the reproductive health of females.
- EEGs are used to measure the electrical activity in the brain via small electrodes that are placed on a person's scalp.
- Molecular biological tests are used to detect the presence of bacterial and viral infections within the body.
References
- Global Solutions Inc, Types of Drug Tests, 2022.
- Mayo Clinic, Electrocardiogram (ECG or EKG), 2022.
- Mayo Clinic, EEG (electroencephalogram), 2022.
- CDC, Sterilization: Monitoring, 2022.
- CDC, HIV Testing, 2022.
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