Molecular Biology Techniques Introduction

Introduction

• Molecular biology is the study of the structure, function, and manipulation of macromolecules essential to life.
• Some major macromolecules include proteins and nucleic acids.

Centrifuge

• Separates substances by size, shape, density, viscosity, and rotor speed.
• Can be used to purify mixtures.
• Employs centrifugal force for separating particles.
• Operates on the principle of sedimentation due to gravitational force.

Microcentrifuge

• Extremely small in design, taking up little space.
• Uses small tube sizes, typically up to 2.0 ml.
• Has a speed range from 500 rpm to 13300 rpm.
• Useful for pelleting nucleic acids, pelleting proteins from solution, and microfiltration of small aqueous samples.

Micropipettes

• Transfer small liquid quantities, typically down to 0.1 uL.
• Used in various laboratories, including chemistry, biology, forensics, pharmaceuticals, and drug discovery.

Eppendorf Tubes

• Small capped plastic tubes.
• Commonly used in centrifuges and PCR apparatuses.
• Available in various volumes like 0.5 ml, 1.5 ml, 2 ml, with 1.5 ml being the most common.

Incubators

• Devices for growing and maintaining microbiological or cell cultures.
• Maintain optimal temperature, humidity, and atmospheric conditions like carbon dioxide and oxygen levels.

Freezers

• Cold cabinets that store biological samples at temperatures ranging from 10°C to -80°C.
• Used in laboratories, hospitals, blood banks, research facilities, and testing centers.
• Essential for preserving sensitive biological samples like DNA.

Thermal Cycler

• Amplifies segments of DNA through the polymerase chain reaction (PCR).
• Utilizes a chain reaction where a small DNA fragment serves as a template for primer production.
• Operates in three stages:
  • Denaturation: Separates double-stranded DNA at 94°C.
  • Annealing: Allows oligonucleotide primers to bind to the template at 54°C.
  • Extension: Synthesizes new DNA strands using thermostable DNA polymerase at 72°C.

Electrophoresis Chamber

• Separates and analyzes macromolecules like DNA, RNA, and proteins based on size and charge.
• Employs an electric field to move molecules through a gel matrix.
• Positively charged molecules migrate toward the negatively charged cathode.
• Negatively charged molecules migrate toward the positively charged anode.

UV Transilluminator

• Used to visualize DNA or RNA separated by gel electrophoresis.
• The gel is stained with a fluorescent dye that binds to nucleic acids.
• Exposing the stained gel to a UVB light source causes the DNA/dye to fluoresce and become visible.

This quiz covers the fundamental techniques used in molecular biology, including the use of centrifuges, microcentrifuges, micropipettes, and Eppendorf tubes. Understand the principles and applications of these tools in studying macromolecules and conducting experiments in the laboratory.