DNA tech. quiz Flashcards
Gene cloning
Produce multiple copies of a single gene and producing abundant protein from that gene.
Restriction enzymes
Discovered in the 1960’s. These enzymes protect bacteria by cutting up foreign DNA at specific sites on a nucleotide sequence.
DNA liagase
An enzyme that permanently bonds sticky ends together.
Cloning vector
The original plasmid from a bacterium. May contain antibiotic resistance genes. This is the circle of DNA you will add your gene of interest to.
Genomic library
- collection of cloned genes in a bacterium.
Ie. Petri dish 1 - colony of bacteria containing the middle of the gene of interest.
Petri dish 2 - colony of bacteria containing the end of the gene of interest.
Petri dish 3 - colony of bacteria containing the beginning of the gene of interest.
In reality genes can be very large and 10s-100s of plates would be needed to house all of the parts of a gene.
BAC
Bacterial Artificial Chromosome
- a plasmid with many genes. These genes may function together, like the lac or tryp operon genes.
cDNA
Complementary DNA made from mRNA with reverse transcriptase. No introns in the cDNA. Just exons that actually code for the needed protein.
Bacterial Expression Vector
A plasmid with a strong promoter upstream from the cloned eukaryotic genes. Causes the expression of the gene.
PCR
Polymerase Chain Reaction
- makes copies of small amounts of DNA.
Gel Electrophoresis
Process separates DNA by size, by moving it through a gel with electricity.
Think of swimming through jello. Smaller pieces move faster than larger pieces.
Southern Blot
Gel electrophoresis of DNA, hybridize with a labeled RNA and ssDNA. Allows you to find a gene of interest.
Northern Blot
Gel electrophoresis of mRNA, hybridization with labeled RNA and ssDNA. Allows you to find mRNA of interest.
Rt-PCR
Isolate mRNA, do PCR, run gel. DNA bands on the gel indicate the presence of the mRNA coding for DNA.
Ie. B-globin mRNA-a, B-globin mRNA-b, etc.
In situ
In the organism
In vitro
In a test tube or non-living test media.
In vivo
In the organism
DNA micro array assays
DNA attached to small glass slides or array. Probed with cDNA.
RNAi
RNA interference
- double stranded RNA matches a gene sequence and block translation of mRNA. Knocks down gene expression.
Totipotent cell
Differentiated cell that can dedifferentiate and form an entire, new adult organism.
Reproductive cloning in mammals
Ie. Dolly - sheep that was cloned from a mammary cell nuclei + an enucleated sheep egg.
Produced a diploid cell which grew to an embryo.
SNP
Single Nucleotide Polymorphism
- a single change in every 100-300 nucleotides. Unique to individuals, like fingerprint.
RFLP
Restriction Fragment Length Polymorphism
A SNP in a gene can change a restriction site –> fragments of lengths other than the usual.
Ie. CCAATT/CCAATT/CCAATT normal gene sequence –> 3 CCAATT fragments
Ie. CCAATT/CCAAGTCCAATT A SNP of T removes one restriction site –> 2 fragments
STR
Short Tandem Repeats
- repeated units of 2 - 5 base pairs in specific regions of a genome. The number of repeats varies from person to person and is an identifier like a fingerprint.
GMO
Genetically Modified Organism
- genes added or removed
Genetic engineering
Manipulation of genes for practical purposes
DNA sequencing
Developed by Sanger 1980. Dideoxyribonucleotide method
Plasmid
Small number of genes, replicates separately from bacterial DNA, may provide antibiotic resistance to the bacterium containing it.
