PCR test (polymerase chain reaction) is a check moleculardone with amplification method or reproduce the genetic material of a virus or bacteria. PCR tests are often performed to detect the presence of viruses or bacteria that cause certain diseases.
One of the sampling methods for the PCR test is the swab test swab test. Examples of diseases that can be diagnosed through PCR tests with sampling methods from swab test is COVID-19.
In addition to the swab test, sampling for the PCR test will be adjusted according to the type of disease you want to diagnose. Several types of samples that can be used for PCR tests are samples of blood, urine, sputum, and even cerebrospinal fluid (CSF).
PCR Test Purpose and Indications
As mentioned above, the PCR test can be used to detect the presence of genetic material present in every living thing, including viruses and bacteria. The ability of PCR tests to detect genetic material can be used to detect a number of infectious diseases, such as:
- Gonorrhea
- chlamydia
- Lyme disease
- Pertussis (whooping cough)
- Cytomegalovirus infection
- Infection hpapillomavirus (HPV)
- Infection hgeneral immunodeficiency virus (HIV)
- Hepatitis C
- COVID-19
Preparation Before Performing the PCR Test
There is no special preparation before carrying out the PCR test. However, the patient will take samples with a special method, to be sent to the laboratory for extraction, purification, and processing by PCR.
Patients undergoing a PCR test need to be told how long it will take for the results of this test to come out. Patients with infectious diseases that can be transmitted through droplet (splashing phlegm), such as COVID-19 or whooping cough, must comply with existing health protocols while waiting for PCR results.
Patients undergoing a PCR test with swab sampling (swab test) need to be given direction that this procedure can cause discomfort, both during the process and after.
Sampling Procedure for PCR Test
One of the sampling methods to be further examined by PCR is through the swab test (swab test). The swab test can be done on the nose, the passage between the nose and throat (nasopharynx), or the passage between the mouth and throat (oropharynx).
Here are the steps swab testt the patient will undergo:
- The doctor will ask the patient to remove the mask and blow the nose from the nose if there is one.
- The doctor will ask the patient to raise his head to facilitate the process of taking the mucus sample.
- The doctor will insert the tool swab resembling cotton bud from the nose to the nasopharynx (the upper part of the throat located at the back of the nose).
- The doctor will rotate or move the instrument swab several times (about 15 seconds) so that the mucus in the nasopharynx sticks to the device swab.
- After the mucus sampling process is complete, the doctor will withdraw the instrument swab slowly and the patient will be asked to put the mask back on.
In addition to the swab test, samples for the PCR test can also be taken from blood, urine, or cerebrospinal fluid. This will be adjusted to the type of disease that you want to detect through the PCR test.
The doctor and medical team will provide direction and carry out sampling procedures according to the needs of the examination. If the sample required is a blood sample, blood will be drawn through a vein using a special needle.
If what is needed is a urine sample, the patient will be asked to collect urine in a special tube, to be sent to a laboratory for analysis. Specifically for cerebrospinal fluid sampling, the doctor will perform a lumbar puncture procedure.
After Sampling Procedure for PCR Test
After the sampling process is complete, the sample will be sent for further processing and reading by the PCR tool. If sampling is done with swab testAfter the mucus sampling process, the doctor will insert a tool swab into a plastic tube, then tightly seal the plastic tube.
This plastic tube will be put into a special tube for hazardous waste (biohazard) and brought to the laboratory for further processing and put into a PCR tool to get results. PCR test results can be known within 1-2 days.
The PCR test involves 3 processes, starting from sampling, extraction of genetic material from the sample, amplification or duplicating of genetic material, and reading of the results. In this examination, the value of will usually be listed CT values.
PCR test results will show positive or negative. A positive result means that the patient is confirmed to have the disease. On the other hand, a negative result means that the patient does not have the disease.
However, in some cases, the PCR test may return false positive or false negative results. A false positive means that the test result is positive, when in fact it is negative. Whereas a false negative is the opposite, indicating a negative when it is actually positive.
For example, a false positive result for COVID-19 means that a person who has undergone a PCR test is considered positive for COVID-19, even though he or she is not infected with the SARS-CoV-2 virus. On the other hand, a false negative result indicates that a person who has undergone a PCR test does not have COVID-19, when in fact he or she is infected with the SARS-CoV-2 virus.
PCR Test Side Effects
The PCR test is safe for everyone to do and does not cause any side effects. It's just that, when taking samples, some complaints can appear, for example a feeling of discomfort in the nose when the doctor inserts the instrument swab or bruising and pain at the injection site when the blood sample is taken.
However, in the absence of certain medical conditions, these side effects will generally go away on their own.