Molecular Biology

This is a molecular biological technique used for amplifying specific DNA sequences. The target DNA sequence can be amplified billions of times. A PCR reaction requires target DNA, free nucleotides, DNA primers and the enzyme Taq polymerase. This enzymatically mediated in vitro amplification of specific target sequence is achieved by simultaneous extension of complementary strands of DNA […]

In this technique, short oligonucleotide (10 bp long) primers are used to amplify nanogram amounts of total genomic DNA by PCR. The oligonucleotide primers bind to complementary sequences in the template DNA and produce discrete DNA products. Nucleotide variation between different sets of template will result in the presence or absence of bands because of […]

Restriction digestion is the process of cutting DNA molecules into fragments with the enzymes called restriction endonucleases. These enzymes act as molecular scissors and cleave the DNA at precise sequence. Restriction enzymes are basically bacterial enzymes that form a part of their defence mechanism against foreign DNA (discussed in chapter 9). The process requires restriction enzymes […]

Blotting techniques are important tools both in molecular biology and in clinical research. These techniques are used to identify proteins and nucleic acids. The blotting techniques generally involve fours steps, namely: There are three main types of blotting techniques, namely: Southern Blotting This is a DNA-DNA hybridization technique. It is often used to identify the […]

Gel electrophoresis uses electricity to separate charged macromolecules by size, as they migrate through a gel matrix. The gel acts as a molecular sieve, as the macromolecular mixture moves through the gel under the influence of an electric field. Thus, the molecules of varying size are separated. DNA Electrophoresis ‘Agarose gel electrophoresis’ is the easiest […]

This chapter provides information regarding the practical side of molecular biology. Molecular biology methods are used extensively in modern-day drug discovery, research and development, and diagnostics. In the previous chapters too, various other techniques in molecular biology such as cloning, FISH, DNA and protein arrays and DNA foot printing had been covered. This chapter focuses […]