2. • Developed by James Alwine, David Kemp and
George Stark in 1977.
• Similarity of name with Southern Blotting but
it analyzes RNA
• To study gene expression by detection of RNA
during differentiation, diseased conditions

3. • Electrophoresis – Seperates RNA on the basis of
their Molecular weight and type in agarose gel
which have EtBr ,an intercalating agent in it.
• Capillary action – RNA bands move towards
blotting paper by capillary movement and
entrap in sheet and buffer moves ahead.

4. Procedure
Extraction of RNA
• From homogenised tissue sample
• RNA with poly A tail
Electrophoresis of RNA
• In agarose gel
• RNA is not fragmented
Transferred to nylon paper or DBM paper
• Because probes are unable to bind with RNA in gel
• Done by capillary action
• Buffer contains formamide to reduce annealing temp.

5. Stabilization
• By Heat or UV rays
• Formation of covalent linkages
Hybridization
• With radiolabelled or fluorescently
labelled probe
Detection
• By X-rays