Analysing DNA Flashcards
What are the main methods of DNA analysis?
DNA extraction
Polymerase chain reaction (PCR)
DNA profiling
Gel electrophoresis
What is the process of DNA extraction?
Cells in the sample are broken open by grinding or blending.
Fats and proteins in the mixture are emulsified by adding detergent and salt.
Ethanol is added and the sample is centrifuged to separate DNA from the rest of the cell debris.
The extracted DNA can then be amplified, sequenced and analyzed.
What are Restriction Enzymes used for in DNA Extraction?
Restriction Enzymes are used to cut DNA in to shorter chains or fragments. They are specific so only cut DNA at a particular sequence, leaving sections of unmatched DNA on each strand called sticky ends.
What is the process of Polymerase chain reaction (PCR) data analysis?
A PCR machine is used to amplify the extracted DNA fragments which can then be used in gene isolation, sequencing, cloning, mapping mutations or studying gene expression.
Samples are put into the machine along with DNA polymerase, primers and nucleotides.
A cycle of automated temperature changes starts the synthesis of new DNA strands by adding complementary nucleotides into the primer.
Each repeat doubles the number of fragments.
What is DNA profiling?
A technique which can identify individuals or relationships. It uses the fact that restriction enzymes cut an individuals DNA into fragments in a way that is unique to the individual.
These fragments are separated by electrophoresis. This gives a pattern that can be used to compare the relationship between two different animals such as to check an animals pedigree is accurate.
What is Gel Electrophoresis?
A technique used in DNA profiling or to identify a gene or analyse proteins.
Different sections of DNA travel different distances depending on how long they are.
The DNA is seen as bands which can be identified using a dye, UV fluorescence or DNA probes specific to a particular gene.
Different samples will be analysed at the same time.
Samples which have bands that travel the same distance contain the same gene.
