Science Education - Basic Biology
Basic Methods in Cellular and Molecular Biology

Using a Hemacytometer to Count Cells
Many biomedical experiments require manipulation of a known quantity of cells, in order to achieve accurate, reproducible, and statistically-relevant ...

Passaging Cells
Cell lines are frequently used in biomedical experiments, as they allow rapid culture and expansion of cell types for experimental analysis. Cell lines ...

PCR: The Polymerase Chain Reaction
The polymerase chain reaction, or PCR, is a technique used to amplify DNA through thermocycling – cyles of temperature changes at fixed time ...

DNA Gel Electrophoresis
DNA gel electrophoresis is a technique used for the detection and separation of DNA molecules. An electric field is applied to a gel matrix comprised of ...

Separating Protein with SDS-PAGE
Sodium Dodecyl Sulfate Poly-Acrylamide Gel Electrophoresis, or SDS-PAGE, is a widely-used technique for separating mixtures of proteins based on their ...

Bacterial Transformation: The Heat Shock Method
Transformation is the process that occurs when a cell ingests foreign DNA from its surroundings. Transformation can occur in nature in certain types of ...

Bacterial Transformation: Electroporation
The term “transformation” refers cellular ingestion of foreign DNA. In nature, transformation can occur in certain types of bacteria. In ...

The ELISA Method
An enzyme-linked immunosorbent assay (ELISA) is typically performed to detect the presence and/or amount of a target protein of interest within an ...

Plasmid Purification
Plasmid purification is a technique used to isolate and purify plasmid DNA from genomic DNA, proteins, ribosomes, and the bacterial cell wall. A plasmid ...

Gel Purification
Gel purification is used to recover DNA fragments after electrophoretic separation. DNA recovery from an agarose gel includes three basic steps: binding, ...

The Western Blot
Western Blotting is used to identify the presence of specific proteins in electrophoretically separated samples. Following separation by a technique ...

An Introduction to Transfection
Transfection is the process of inserting genetic material, such as DNA and double stranded RNA, into mammalian cells. The insertion of DNA into a cell ...

DNA Ligation Reactions
In molecular biology, ligation refers to the joining of two DNA fragments through the formation of a phosphodiester bond. An enzyme known as a ligase ...

Restriction Enzyme Digests
Restriction enzymes or endonucleases recognize and cut DNA at a specific sequence. These enzymes occur naturally in bacteria as a defense against ...

Molecular Cloning
Molecular cloning is a set of methods, which are used to insert recombinant DNA into a vector - a carrier of DNA molecules that will replicate recombinant ...