Part 10: Molecular Biology Techniques
Tools of the Trade
Modern molecular biology relies on powerful techniques to manipulate, analyze, and visualize DNA, RNA, and proteins. These methods have revolutionized our understanding of life and enabled biotechnology, medicine, and genetic engineering.
DNA Analysis Techniques
PCR (Polymerase Chain Reaction)
Amplifies specific DNA sequences exponentially
Cycle: Denaturation (95°C) → Annealing (50-60°C) → Extension (72°C)
Components: Template, primers, dNTPs, Taq polymerase
Result: 2ⁿ copies after n cycles
DNA Sequencing
Sanger Sequencing
Chain termination with ddNTPs. Gold standard for accuracy. ~1000 bp reads.
Next-Gen Sequencing
Massively parallel. Illumina, PacBio, Nanopore. Millions of reads.
Gel Electrophoresis
Separates DNA/RNA/proteins by size. Agarose (DNA) or polyacrylamide (proteins, small nucleic acids).
Cloning & Engineering
Molecular Cloning
- • Restriction enzymes cut DNA
- • Ligase joins fragments
- • Vectors: plasmids, phage, BACs
- • Transformation into host cells
CRISPR-Cas9
- • Guide RNA directs Cas9 nuclease
- • Creates targeted DSBs
- • Gene knockout, knock-in, editing
- • Revolutionary for research & therapy
Protein & RNA Analysis
Western Blot
Detects specific proteins using antibodies
Northern Blot
Detects specific RNA sequences
Southern Blot
Detects specific DNA sequences
RT-qPCR
Quantifies gene expression (mRNA levels)
RNA-seq
Transcriptome-wide expression profiling
Mass Spectrometry
Protein identification and quantification
X-ray Crystallography
Determines 3D protein structures
Cryo-EM
Structure determination without crystals
Congratulations!
You've completed the Molecular Biology course! You now have a foundation in DNA structure, replication, repair, transcription, translation, gene regulation, recombination, and laboratory techniques.