Recombinant DNA Technology Vocabulary

A comprehensive vocabulary review of tools, concepts, and applications in Recombinant DNA Technology based on the lecture slides.

Recombinant DNA Technology

The techniques involved in manipulating DNA by inserting genes from another organism into another DNA to alter the characteristics of an organism.

Recombinant DNA

A DNA molecule made in vitro by combining genes from different organisms or sources.

Target DNA

A fragment of DNA containing the gene of interest to be cloned that will be inserted into the host cell to produce the desired protein.

Restriction Enzyme

Enzymes extracted from bacteria that recognize and cleave or cut DNA into fragments at specific base sequences called restriction sites.

Sticky Ends

Double-stranded DNA fragments with unpaired bases / single-stranded DNA at the 5' or 3' ends, produced when a restriction enzyme cuts across both DNA strands in a staggered way.

Blunt Ends

Double-stranded DNA fragments with no unpaired bases at the ends, produced when a restriction enzyme cuts straight across both DNA strands at the same position.

Palindromic Sequence

A restriction site sequence where the base sequence of one strand reads the same as its complementary strand when both are read in the 5' to 3' direction on double-stranded DNA.

EcoRI

A restriction enzyme isolated from Escherichia coli that cuts DNA at the sequence 5'-GAATTC-3' in a staggered manner to produce sticky ends.

SmaI

A restriction enzyme isolated from Serratia marcescens that cuts DNA at the sequence 5'-CCCGGG-3' in a straight manner to produce blunt ends.

DNA Cloning Vector

A DNA molecule (such as a plasmid or virus) that can carry foreign DNA into a host cell and replicate there in genetic engineering.

Multiple Cloning Site (MCS)

A short segment of DNA in a cloning vector containing many restriction sites where restriction enzymes can cut the vector to insert a target gene.

Origin of Replication (ori)

A specific sequence in a plasmid that enables it to replicate independently and freely in the host cell.

Selectable Marker Gene

Genes present on a cloning vector (such as ampR and lacZ) used during selection and screening to identify host cells containing plasmid or recombinant DNA.

Host Cell

An organism or cell (such as E. coli) used to receive a recombinant DNA molecule for cloning purposes.

Transformation

The process by which recombinant DNA is transferred or introduced into host cells.

Competent Cells

Host cells that have been treated with cold calcium chloride to increase the permeability of their cell wall towards plasmid DNA prior to transformation.

DNA Ligase

A modifying enzyme that catalyzes the joining of a foreign DNA fragment and a cloning vector by forming phosphodiester bonds between complementary sticky ends.

Taq Polymerase

A heat-stable DNA polymerase isolated from Thermus aquaticus that adds DNA nucleotides to the 3' end of primers during PCR extension.

Polymerase Chain Reaction (PCR)

An in vitro technique used to amplify small amounts of DNA into millions of copies through repeated cycles of denaturation, annealing, and extension.

Reverse Transcriptase Polymerase Chain Reaction (RT-PCR)

A technique in which mRNA molecules are converted into cDNA by reverse transcription, followed by the amplification of cDNA using PCR.

Complementary DNA (cDNA)

Double-stranded DNA synthesized in vitro from single-stranded mRNA using reverse transcriptase and DNA polymerase, containing no introns.

Bioremediation

The use of biotechnology to process or degrade a variety of natural and manmade pollutants in air, water, and soil.

Blue Colonies

Colonies formed on X-gal media by transformed bacteria carrying non-recombinant plasmids with an intact lacZ gene that produces functional β-galactosidase.

White Colonies

Colonies formed on X-gal media by transformed bacteria carrying recombinant plasmids with a disrupted lacZ gene that cannot produce β-galactosidase.