LAI PHAÂN TÖÛ
(MOLECULAR HYBRIDIZATION)
CHÖÔNG 4
Concept of hybrid molecules
•When double strand DNA is steamed to a temperature
exceed the melting temperature (Tm), it will separate
into 2 single strands DNA due to breaks of H bonds. If
the reaction temperature is then decreased slowly plus
other appropriate experimental conditions, these
ssDNA will pair again. This phenomenon is called the
hybridization of molecules.
•Characteristic of the hybrid molecules: Specificity, the
re-pairing occurs only between two complementary
sequences.
•These complementary sequences can be DNA or RNA,
leading to the formations of DNA-DNA, RNA-RNA or
hybrid DNA-RNA
TYPES OF HYBRIDIZATION
•- Hybrid in liquid phase (Lai trong pha
loûng)
•- Hybrid on solid phase (Lai treân pha
raén)
•- in situ hybridization (Lai taïi choã)
•- Southern Blot
•- Northern Blot
•- Western Blot
•First described by E. M. Southern in
1975.
•Applications of Southern
hybridization
–RFLP’s, VNTR’s (Variable Number
Tandem Repeat) and DNA fingerprinting
–Checking of the gene knockout mice
Southern Blot (1975)
Northern Blot (1977)
Technique for detecting specific RNAs
separated by electrophoresis by
hybridization to a labeled DNA probe.
-Transfer RNA onto membrane
-Hybridize with probe
-Detection