MATERIALS 6x Gel-loading buffer Agarose solutions (please see Step 3) DNA samples DNA size standards Samples of DNAs of known size are typically generated by restriction enzyme digestion of a plasmid or bacteriophage DNA of known sequence. Alternatively, they are produced by ligating a monomer DNA fragment of known size into a ladder of polymeric forms. DNA staining solution For a discussion of...

Gel electrophoresis is a widely known group of techniques used to separate and identify macromolecules as DNA, RNA, or proteins based on size, form, or isoelectric point. The separation of molecules by electrophoresis is based on the fact that charged molecules migrate through a gel matrix upon application of an electric field. These techniques have become a main tool in biochemistry, molecular...

Agarose gel electrophoresis is used to separate DNA or RNA molecules based upon their size.

Polyacrylamide gels are typically formed by polymerization of the monomer acrylamide crosslinked to the co-monomer, N,N’-methylenebis-acrylamide, commonly called BIS. This process is a freeradical polymerization that requires an initiator, usually ammonium persulfate, and a catalyst like N,N,N’,N’-tetraethylmethylenediamine (TEMED). A distinct advantage of polyacrylamide gel systems is that by ...

Electrophoresis is widely used as a separative technique, particularly in protein chemistry. In some respects gelatinous media have an advantage over others as support media for electrophoresis, perhaps most obviously when a gel matrix of molecular dimensions is employed, allowing the simultaneous use of two properties for separation of the particles of interest-size and surface charge density....

INTRODUCTION Alkaline agarose gels are run at a pH that is sufficiently high to denature double-stranded DNA. The denatured DNA is maintained in a single-stranded state and migrates through the alkaline gel as a function of its size. Alkaline agarose gels are used chiefly to measure the size of first and second strands of cDNA (Construction of cDNA Libraries Stage 1: Synthesis of First-strand c...

U.V. scanning may readily be performed on unstained agar-gel strips in the dry state. Polyacrylamide gels tend to become brittle if dried; whether they can be reliably scanned in the undried state, as unstained strips or columns, depends on whether there are troubles due to deformation of the pattern when the gel is manipulated, or to optical opacity. With proteins, if not with RNA, u.v.-sensit...