Session 8 Flashcards
What is Northern blotting used to analyse?
RNA
Briefly explain the process of Northern blotting.
Uses reverse transcriptase PCR to produce cDNA from mature mRNA: creates an amplified sequence of cDNA. The cDNA is the used to undergo gel electrophoresis.
Why is microarray technology used?
To investigate 1000s of genes simultaneously in order to investigate chromosome deletions/duplications and conditional gene expression.
What is DNA fingerprinting used for?
Allows family relationships to be shown: useful for paternity disputes.
Also useful in forensics.
What is karyotyping?
Method used to visualise the number and appearance of chromosomes in the nucleus of a eukaryote. Displays a complete set of chromosomes from the cell.
What is FISH.
Fluorescence in situ hybridisation.
Specific areas on a chromosome are labelled with fluorescent dye by denaturing the sequence and hydrolysing it with the dye.
Allows chromosomes to be “painted” to investigate positions of certain sequences of DNA.
Why is FISH used?
To investigate genes in situ, chromosome structure, chromosome number and chromosome behaviour.
Briefly explain the process of Sanger sequencing.
DNA sample is divided for 4 separate reactions, each reaction contains 4 standard deoxynucleotides and one of the 4 dideoxynucleotides. DNA is denatured with heat and Taq polymerase is used to produce double strands of DNA, creating fragments of different lengths are because dideoxynucleotides cause termination of polymerase. Strands are separated using gel electrophoresis and the DNA bands are visualised using a computer to show the sequence of the original DNA.
What is southern blotting used for?
To detect the presence of DNA on an electrophoretorgram using allele-specific labelled DNA probes.
