Indirect ELISA

Indirect ELISA is used for detection of a particular antibody in a given sample. Most of the HIV diagnosis kits use indirect ELISA principle.

Indirect ELISA

In this type of ELISA, the antigen (viral coat in case of HIV) are adsorbed to the walls of well.

Antibodies from patient are then added to the well.

If the patient is HIV positive he will produce antibodies against the HIV antigen and if he is HIV negative, there won�t be any antibodies against the antigen.

After that, detection antibodies which will recognize human antibodies are added.

The unbound detection antibodies are washed off followed by substrate addition.

If the sample contains antibodies against HIV, it will show a colour change due to the detection antibody bound to it.

If the sample is HIV negative, it won�t show ant colour change as it does not have any bound detection antibody.

Written by Komal Kadam
Illustration by Immense Immunology Insight

Sandwich ELISA

To remember this type of ELISA, imagine a sandwich! The antigen is the filling and the antibodies are the yummy bread. Hungry, aren't you?

Sandwich ELISA

In this type of ELISA, an antibody of a particular antigen is adsorbed to the walls of well.

Then sample antigens are added.

If the sample contains desired antigen it will bind to the antibody.

After the unbound antigens are washed off, detection antibodies which bind specifically to desired antigen are added.

Unbound detection antibodies are washed off followed by substrate addition.

Sample containing bound detection antibody will give colour change indicating the presence of  antigen and the sample which do not have any bound detection antibody will be colourless.

Written by Komal Kadam
Illustration by Immense Immunology Insight

ELISA: Enzyme Linked Immuno Sorbent Assay

ELISA: Enzyme Linked Immuno Sorbent Assay

From pregnancy detection kits to HIV diagnosis it is ELISA which gives us appropriate results.  

Though ELISA has got a complex name, the way in which it diagnosis is really simple!

ELISA is performed in special micro titre plates which has wells in which we add our sample and then perform ELISA.

There are 4 types of ELISA:

- Direct

- Indirect

- Sandwich
- Competitive

We�ll explain them one by one over the next few blogs. So stay tuned! :)

Written by Komal M. Kadam

Acute Myelogenous Leukemia Fighter

I am raising awareness about hematological malignancies this month.

Today, it's all about acute myelogenous leukemia. It's when your white cells divide endlessly. They aren't functional which makes you suspectible to infections. These cells also take up space in the bone marrow, causing your red blood cell counts and platelet counts to go down. This makes you tired and very prone to bleeding.

To everyone fighting leukemias, cancer isn't cute. But you are. Don't give up!