DNAIsolation

Onion DNA Isolation

DNA Thought for the day:“The capacity to blunder slightly is the real marvel of DNA.  Without this special attribute, we would still be anaerobic bacteria and there would be no music.”  ~Lewis Thomas

Human cheek Cells

Why should the DNA extraction procedure be universal and able to be used on all

types of cells?

Emulsification

What is the name given to a molecule that has both polar and nonpolar properties?

What Electrical Charge Does DNA Have?

When we visualize DNA we need thousands of molecules of DNA to come together.

Why would charge be important?

The knobs do not correspond to any temperature!

600c is critical!

Chopped Onion

Note consistency: The liquid should become thicker

WWhat is meat tenderizer?

Why is it used here?Why can’t you use fresh pineapple when making

Jello?

Precipitate- Change from a liquid to a solid

It is so cool!

You will be graded on the amount of DNA you isolate, so be careful!

Safety First!

Eye SafetySharp Object

Safety

Heat Safety

One More Time!

DNA Isolation Procedure

Step 1: Mash piece of onion well for 2 minutes. Place in Ziploc bag

Step 2: Pour ~20mL of detergent solution into the bag.

Step 3: Add two shakes of meat tenderizer to the bag. Mash together for 1 minute.

Step 4: Place bag in hot water bath at 55-60O C for 15 min.

Caution – Do not let temp of water bath exceed 60O C and no less than 50O C.

Step 5: Place bag in ice water bath for 5-10 min to get the Temperature of the mixture down to 10O C.

.

Step 6: Set up filtration system and slowly pour contents of bag into filter paper.

Step 7: Pour filtrated solution into beaker. Discard filter paper.

Step 8: Slowly pour ~20mL of iced cold Alcohol solution into50ml beaker.

Step 9: Observe DNA precipitating into the alcohol.