Correct option is D
Explanation-
Passive agglutination is an enhanced form of agglutination where antigens are coated onto inert particles (like latex beads or charcoal), increasing their visibility and amplifying the detection even at very low concentrations. It is highly sensitive compared to diffusion or electrophoretic methods. This is commonly used in diagnosis of diseases like rheumatoid arthritis, CRP levels, and various viral infections.
Incorrect Options -
Option a - Immuno-electrophoresis – Good for separating and identifying proteins, but it's less sensitive and more time-consuming.
Option b - Rocket electrophoresis – A quantitative immunodiffusion method, but still less sensitive compared to agglutination-based assays.
Option c - Immunofluorescence – While sensitive, it typically requires microscopy and expertise, and in standard diagnostic use, passive agglutination offers more practical high sensitivity in many routine assays.
Final Answer: Option d – Passive agglutination
