**ELISA Test Results and Analysis for COVID-19**You are running an ELISA to test three patients for COVID-19. The results of the test are shown below. What statement is TRUE based on the results shown?**Diagram Description:**The diagram is a grid with three rows and five columns. - **Rows (Dilutions):** - 1:2 dilution - 1:10 dilution - 1:100 dilution- **Columns (Samples and Controls):** - Patient A - Patient B - Patient C - Positive Control - Negative Control**Results:**- **Patient A:** All circles (1:2, 1:10, 1:100) are white, indicating a negative result.- **Patient B:** The 1:2 dilution is yellow, while the 1:10 and 1:100 dilutions are white, suggesting a weak positive result.- **Patient C:** All circles are white, indicating a negative result.- **Positive Control:** All circles are yellow, confirming the test validity showing a positive reaction as expected.- **Negative Control:** All circles are white, confirming the test validity showing a negative reaction as expected.**Statements:**- k. Patient A has COVID-19.- l. Patient B has COVID-19.- m. Patient C has COVID-19.- n. Patients B and C have COVID-19.- o. Patients A and B have COVID-19.**Analysis:**Based on the ELISA results, Patient B shows a positive result at the 1:2 dilution, while Patients A and C show negative results across all dilutions.**Correct Statement:**l. Patient B has COVID-19.

ELISA (enzyme-linked immunosorbent assay) is a enzyme linked analytical assay in which presence of protein/antigen can be detected using antibodies in liquid sample. It is a commonly used method as a diagnosis tool in medicine, biotechnology research and also for quality control process. Four types of ELISA are known based on the antigen and antibody type of interaction - 1. Direct ELISA, 2. Indirect ELISA, 3. Sandwich ELISA and 4. Competitive ELISA. Dilution of antibody (Ig) in ELISA is done to determine the minimum concentration range of Ig in which it can detects the antigen/protein.In given ELISA, serial dilution of 1:2, 1:10 and 1:100 for covid-19 antibody (Ig) are used for quantitative detection of covid-19 antigen. From the result of ELISA, we can see that positive COVID-19 antigen result with patient B and C, while patient A shows negative result in all three dilutions. But, if we look into the dilution of patient B, we can see that at 1:2 dilution it shows a negative result and at 1:10 it shows positive result. This is itself a contradictory result data. i.e. if we can the positive result at higher dilution, then we must get positive result at lower dilution than that. "Higher the dilution less the quantity of antibody and vice-versa. i.e. 1:10 dilution contains less antibody than the 1:2 dilution". Patient B data shows some kind of error as it is impossible to detect the antigen at 1:10 dilution if not able to detect at lower dilution of 1:2. Whereas, patient C is sensitive at both lower (1:2) and higher (1:10) dilutions i.e. positive result and negative result at 1:100 dilution. This shows that the range of antibody sensitivity for patient C is 1:2 to 1:10. Thus, m. patient C has positive COVID-19 result and rest of options are incorrect. k. incorrect answer l. incorrect answer m. Correct answer n. incorrect answer o. incorrect answer