When doctors want to detect one of several diseases in patients, they usually recommend performing an ELISA or enzyme linked-immunosorbent assay test. The test can help doctors confirm their diagnosis. It is a blood test to detect antibodies in the bloodstream.  An ELISA test is effective in identifying situations when the immune system becomes prone to making antibodies. Swab tests are not enough to identify certain diseases and, in such cases, ELISA blood tests can help spot signs of disease or infection in your system. Covid-19 ELISA Kits are the new addition to similar test kits used for detecting other diseases such as HIV, Lyme disease, Rocky Mountain spotted fever, Pernicious anemia, Syphilis, and Squamous cell carcinoma. 

Working modality of ELISA test kits

Special enzymes used during the ELISA tests tend to attach to antibodies in the blood sample. The test requires taking a blood sample with a known compound by using special absorbent plates. Depending on the purpose of the test based on what the doctor wants to diagnose, the enzymes used for testing would vary as different enzymes can detect different antibodies. If the blood contains the antibody that the doctor is looking for, the enzymes would attach to the plate. If the test is positive, the color of the plate changes, and the color remain unchanged if the outcome is negative. Based on the change, it is possible to ascertain whether you have a certain condition. Moreover, in certain cases, the test also indicates the severity of the condition.

The procedure of drawing the blood sample

 An ELISA test is quick and easy as the patient only must give a blood sample to the lab for testing. The process of drawing the blood sample is no different from carrying out other blood tests. The lab technician drawing the blood sample from you will first sterilize your elbow with an antiseptic wipe. To make the blood draw site more visible, they will also tie a tourniquet to your upper arm. Then after placing a needle in your arm, they will draw the required amount of blood in a syringe and transfer it into a vial. They will then send the sample to the lab for testing.

After drawing the sample, the lab technician or health worker will remove the needle and ask you to hold it tightly at the site of sample collection. This helps to prevent bleeding and facilitates blood clotting. After putting the pressure on for a few minutes, the health worker may give you an arm wrap and tell you when to remove it. 

Testing for Covid-19

ELISA test kits gained popularity for testing Covid-19 because the testing process is simple and much more affordable than the RT-qPCR test which involves taking swap samples from the nostrils. The cost of the test is less not only because the test is less complex but also because it uses more available and affordable instruments. 

Moreover, as antibodies and antigens are more stable than RNA, the possibility of false-negative results reduces drastically.  The scope of collecting samples from many places of the body increases the accuracy of the test.