tailieunhanh - Lecture Molecular biology: Chapter 5 - Robert F. Weaver

In this chapter we will describe the most popular techniques that molecular biologists use to investigate the structure and function of genes. Most of these start with cloned genes. Many use gel electrophoresis. Many also use labeled tracers, and many rely on nucleic acid hybridization. We have already examined gene cloning techniques. Let us continue by briefl y considering three other mainstays of molecular biology research: molecular separations including gel electrophoresis; labeled tracers; and hybridization. | Molecular Biology Fourth Edition Chapter 5 Molecular Tools for Studying Genes and Gene Activity Lecture PowerPoint to accompany Robert F. Weaver Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Molecular Separations Often mixtures of proteins or nucleic acids are generated during the course of molecular biological procedures A protein may need to be purified from a crude cellular extract A particular nucleic acid molecule made in a reaction needs to be purified 5- Gel Electrophoresis Gel electrophoresis is used to separate different species of: Nucleic acid Protein 5- DNA Gel Electrophoresis Melted agarose is poured into a form equipped with removable comb Comb “teeth” form slots in the solidified agarose DNA samples are placed in the slots An electric current is run through the gel at a neutral pH 5- DNA Separation by Agarose Gel Electrophoresis DNA is negatively charged due to phosphates in its backbone and moves to anode, | Molecular Biology Fourth Edition Chapter 5 Molecular Tools for Studying Genes and Gene Activity Lecture PowerPoint to accompany Robert F. Weaver Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Molecular Separations Often mixtures of proteins or nucleic acids are generated during the course of molecular biological procedures A protein may need to be purified from a crude cellular extract A particular nucleic acid molecule made in a reaction needs to be purified 5- Gel Electrophoresis Gel electrophoresis is used to separate different species of: Nucleic acid Protein 5- DNA Gel Electrophoresis Melted agarose is poured into a form equipped with removable comb Comb “teeth” form slots in the solidified agarose DNA samples are placed in the slots An electric current is run through the gel at a neutral pH 5- DNA Separation by Agarose Gel Electrophoresis DNA is negatively charged due to phosphates in its backbone and moves to anode, the positive pole Small DNA pieces have little frictional drag so move rapidly Large DNAs have more frictional drag so their mobility is slower Result distributes DNA according to size Largest near the top Smallest near the bottom DNA is stained with fluorescent dye 5- DNA Size Estimation Comparison with standards permits size estimation Mobility of fragments are plotted v. log of molecular weight (or number of base pairs) Electrophoresis of unknown DNA in parallel with standard fragments permits size estimation Same principles apply to RNA separation 5- Electrophoresis of Large DNA Special techniques are required for DNA fragments larger than about 1 kilobases Instead of constant current, alternate long pulses of current in forward direction with shorter pulses in either opposite or sideways direction Technique is called pulsed-field gel electrophoresis (PFGE) 5- Protein Gel Electrophoresis Separation of proteins is done using a gel made of polyacrylamide (polyacrylamide .

• Sinh học
• Molecular biology
• Lecture Molecular biology
• Sinh học phân tử
• Amino acids
• Molecular tools
• Studying genes
• High Yield cell and molecular biology
• Cell and molecular biology
• The cell cycle
• Molecular biology of cancer
• Cell biology of the immune system
• Molecular biology techniques
• Identification of human disease genes
• Campbell biology
• Lecture Campbell biology
• Biological sciences
• Systems biology
• Molecular biology of the gene
• Chromosome replication
• Meiosis and genetic recombination
• The human nuclear genome
• The human mitochondrial genome
• Molecular cloning methods
• Gene cloning
• Directional cloning
• History of genetics
• Both simple
• Molecular genetics
• Genetic code
• Molecular biology of microorganisms
• Different facets
• Plant molecular biology
• Genetic manipulation
• Recombinant DNA technology
• Molecular diagnostics
• Biochemistry cell and molecular biology test
• Molecular Biology Test
• Biochemistry Test
• Genetics test
• Structural Biology
• Cupramolecular complexes
• Lecture Biology
• Mendel’s Laws
• Transmission genetics
• Mendel’s gene transmission
• Genetic material
• Transforming material
• DNA structure
• Gene function
• Storing information
• Mechanism of transcription
• RNA polymerase structure
• Lac operon
• Bacterial transcription
• Sigma factor switching
• DNA Protein interactions
• The λ family of repressors
• Eukaryotic RNA polymerases
• RNA polymerases
• Class II factors
• Transcription activators in eukaryotes
• RNA polymerase II
• Histones in the nucleosome
• Nucleosome structure
• Messenger RNA processing I
• Genes in pieces
• RNA processing II
• Cap structure
• Cytoplasmic polyadenylation
• RNA processing
• Ribosomal RNA processing
• Transfer RNA processing