DNA Technology

DNA technology

techniques for sequencing and manipulating DNA

Genetic engineering

direct manipulation of genes for practical purposes

PCR

a method for producing billions of copies of a specific DNA sequence in a short time

PCR Components 

1. Template DNA 

2. dNTPs

3. DNA primers

4. TAQ polymerase 

Template DNA

sample containing the DNA sequence that is going to be amplified

dNTPS

building blocks used by PCR to create a new strand

• A, T, G, C

DNA Primers 

short DNA fragments with specific sequences at each end of the target DNA sequence 

TAQ Polymerase

heat resistant DNA polymerase

3 Steps of PCR 

1. denaturation

2. annealing 

3. DNA synthesis (extension)

Thermal cycler

a machine that can precisely modulate the temperature of a mixture

Denaturration

heat separates the double helix and breaks the H-bonds

• ~ 90 degrees celsius

Annealing

strand is cooled down and DRNA primers bind with thier complementary sequences

• ~ 40-65 degrees Celsius

DNA synthesis (extension)  

TAQ polymerase joins the strand at the 3’ end and continues to synthesis it

• ~ 72 degrees Celsius 

Gel electrophoresis

a technique used for separating molecules by size 

• confirm PCR results

Gel electrophoresis steps

1. Make a polysaccharide gel

2. Load DNA in wells

3. Pass an electrical current through the gel

4. Smaller DNA fragments move faster than larger ones

Gel electrophoresis uses

Confirm successful PCR 

DNA sequencing 

DNA profiling 

Disease diagnosis 

DNA Sequencing

generates different-sized fragments from the template strand

DNA Barcoding

uses a sequence of the DNA to identify a species

Gene therapy

used to treat a type of genetic blindness

CRISPR

a tool used to silence or insert a gene