Immuno chromatography (ICT)

This ppt explain the components, principle, and application of ICT

1. Lateral flow immunochromatographic assays (ICA) Dr. Aman Ullah B.Sc. MLT Ph.D. Microbiology

2. Introduction Immunochromatography assay (ICA), namely lateral flow test, is a simple device intended to detect the presence or absence of the target analyte The concept of immune-chromatography is a combination of chromatography and immunochemical reactions The most widespread immunochromatographic system is the test strip

3. ICA or ICT strips also known as device

4. Component of ICT strip

5. Component of ICT strip There are four main components of ICT Strips Sample Application Pad Conjugate Pad Substrate(Nitrocellulose) Membrane Adsorbent Pad

6. Sample Application Pad Made of cellulose and/or glass fiber and sample is applied on it Its function is to transport the sample to other components Sample pad should be capable of transportation of the sample in a smooth, continuous and homogenous manner This pretreatment may include separation of sample components, removal of interferences, adjustment of the pH, etc.

7. Conjugate Pad & Substrate(Nitrocellulose) Membrane Conjugate pad: The place where labeled antibodies, usually nano colloid gold particle are dispensed Material of conjugate pad should immediately release labeled conjugate upon contact with moving liquid sample Nitrocellulose membrane: Test and control lines are drawn over the Nitrocellulose membrane by immobilizing the capture antibody onto the strip membrane

8. Adsorbent Pad It works as sink at the end of the strip It also helps in maintaining flow rate of the liquid over the membrane It stops back flow of the sample All these components are fixed or mounted over a backing card, which serves as a support and it makes easy to handle the strip

9. Principle of sandwich assay In this assay format, label antibody is immobilized at conjugate pad This is a temporary adsorption which can be flushed away by flow of any buffer solution A capture antibody against target analyte is immobilized over test line A secondary antibody against labeled antibody is immobilized at control zone 

10. Interpretation of the result

11. Questions/suggestions [email protected]