Nohern blot test is used for:

B i.e. RNA analysis - Blotting techniques separate fragments on the basis of their mass (size) by agarose or SDS- polyacrylamide gel electrophoresis (SDS-PAGE) and then transfer the pattern to nitrocellulose/nylon paper (blotting or adsorption). Then enzyme/radioactive/or fluorescence labeled probe is added complementing, hybridizing & detecting the desired fragment. Southern blotting, Nohern blotting and Western blotting techniques (Mn - "See No West") are used respectively to analyze DNA, mRNA and proteins sampleQ (sequence of protein synthesis). And the probes used in these techniques are c-DNA, cDNA and antibody respectively. - Antigen-antibody reaction is detected by ELISA (enzyme linked immune sorbent assay) and Western (immuno) blot. ELISA is sensitive and Western blot is confirmatory in AIDS diagnosisQ