DNA Extraction and Isolation Presentation Name Course Name Unit # – Lesson #.# – Lesson Name DNA Extraction and Isolation

Presentation Name Course Name Unit # – Lesson #.# – Lesson Name DNA in the Cell DNA is found in cells, particularly in the nucleus or most animal and plant cells.

Why Extract the DNA? Genetic testing Body identification Presentation Name Course Name Unit # – Lesson #.# – Lesson Name Why Extract the DNA? Genetic testing Body identification Forensic evidence analysis

How do we get the DNA from cells? Presentation Name Course Name Unit # – Lesson #.# – Lesson Name How do we get the DNA from cells? Extracting and Isolating DNA from cells take place in essentially 3 steps: Additional step for plant cells: grind plant matter to break cell walls Lysing (breaking) the cells to release DNA Separating cellular and protein debris from DNA Precipitating and isolating the DNA

Presentation Name Course Name Unit # – Lesson #.# – Lesson Name Grinding Plant Matter Plant cells contain cell walls which are tough and surround the cell membrane Plant material should be physically ground so that the cells walls are broken down

Step 1: Lysing Cellular and Nuclear Membranes Presentation Name Course Name Unit # – Lesson #.# – Lesson Name Step 1: Lysing Cellular and Nuclear Membranes Both cell (plasma) and nuclear membranes are made of lipid (fat)-based molecules called phospholipids in 2 layers called a bilayer Nuclear membrane is a double bilayer

Step 1: Lysing Cellular and Nuclear Membranes Presentation Name Course Name Unit # – Lesson #.# – Lesson Name Step 1: Lysing Cellular and Nuclear Membranes A lysis buffer which contains a mild detergents helps to break apart both the cell and nuclear membrane to release the DNA contents

Step 2: Separating Debris from DNA Presentation Name Course Name Unit # – Lesson #.# – Lesson Name Step 2: Separating Debris from DNA DNA is wrapped in a tightly coiled form called a chromosome DNA wrap around proteins called histones so that the coiling is more compact

Step 2: Separating Debris from DNA Presentation Name Course Name Unit # – Lesson #.# – Lesson Name Step 2: Separating Debris from DNA Adding salts (and proteases, enzymes that break down proteins) helps to remove the histones and other protein debris by neutralizing the DNA’s charge

Step 3: Precipitating the DNA Presentation Name Course Name Unit # – Lesson #.# – Lesson Name Step 3: Precipitating the DNA The DNA is still dissolved in water at this point. Adding cold alcohol (either ethanol or isopropanol) will make DNA less soluble in water and it will precipitate out in the alcohol layer (top layer)