Products Details

Covid 19 (IgM + IgG + IgA) Microlisa test is an enzyme immunoassay based on “Double Antigen Sandwich ELISA”.

Covid 19 antigens are coated onto microtiter wells. Specimens and controls are added to the microtiter wells and incubated.

Covid antibodies (IgM, IgG and/or IgA) if present in the specimen, will bind to the Covid-19 antigens absorbed onto the surface of the wells. The plate is then washed to remove unbound material. Horseradish peroxidase (HRP) conjugated Covid-19 antigens is added to each well. This conjugate will bind to covid antigen-antibody complex present in the microwells. Finally substrate solution containing chromogen and hydrogen peroxide is added to the wells and incubated. A blue colour will develop in proportion to the amount of Covid antibodies present in the specimen. The colour reaction is stopped by a stop solution. The enzyme substrate reaction is read by EIA reader for absorbance at a wavelength of 450 nm. If the sample does not contain Covid antibodies then enzyme conjugate will not bind and the solution in the wells will be either colourless or only a faint background colour develops.

The performance of Covid 19 (IgM + IgG + IgA) Microlisa has been evaluated inhouse with the panel of 345 clinical serum/ plasma samples. The sensitivity was checked with 60 positive samples of patients with confirmed COV-SARS-2 infection.The specificity is checked with a panel of 263 negative samples and 22 cross-reacting samples with other diseases; HIV, HCV, HBV, Dengue, Chikungunya, Leptospira,Malaria, Typhi, Rheumatoid factor positive, CRP positive and ASO positive samples.The results obtained are as follows:

PERFORMANCE CHARACTERISTICS

No. of Samples	Status	Covid 19 (IgM + IgG + IgA) Microlisa
		Positive	Equivocal	Negative
60	Covid Positive	59	0	1
263	Covid Negative	0	0	263
22	Covid Reacting	0	0	22

Sensitivity : 96.72% Specificity : 100%

The performance of 3 batches of Covid 19 (IgM + IgG + IgA) Microlisa has also been validated by ICMR, NARI, Pune. The results obtained are as follows:

Precision : Within-run and between-run precisions have been determined by testing 10 replicates of seven specimens : two negative and five weak covid positive. The C.V.(%) of negative and weak positive values were within 15%.