What caused the strawberry DNA to precipitate?
Table of Contents
What caused the strawberry DNA to precipitate?
For DNA extraction, detergent is used to lyse the cell so that DNA is released into the solution. Then alcohol is added to cause the DNA to precipitate out.
What does cold ethanol do in strawberry DNA extraction?
DNA is least soluble in cold ethanol, so make sure to keep the ethanol in the freezer or on ice. When the students add ethanol to their strawberry extract, they will see the fine white strands of DNA precipitate. The DNA will form cotton like fibers that will spool onto the stirring rod/inoculating loop/popsicle stick.
How does salt affect strawberry DNA extraction?
When you added the salt and detergent mixture to the smashed strawberries, the detergent helped lyse (pop open) the strawberry cells, releasing the DNA into solution, whereas the salt helped create an environment where the different DNA strands could gather and clump, making it easier for you to see them.
Why were strawberries used for the DNA extraction experiment?
Strawberries are soft and easy to pulverize. Strawberries have large genomes; they are octoploid, which means they have eight of each type of chromosome in each cell. Thus, strawberries are an exceptional fruit to use in DNA extraction labs and strawberries yield more DNA than any other fruit (i.e. banana, kiwi, etc.).
Why is cold ethanol used in DNA extraction?
Lab technicians can add ethanol or isopropyl alcohol (rubbing alcohol) so that the DNA clumps and form a visible white precipitate. It’s important to use cold alcohol because it allows a larger amount of DNA to be extracted. If the alcohol is too warm, it may cause the DNA to denature [bold], or break down.
How do you preserve strawberry DNA?
Preserve your strawberry DNA in a separate plastic bag or other container in the refrigerator.
What is the role of ice cold environments in working with DNA?
Why is cold important? Using ice-cold water and ice-cold alcohol will increase your yield of DNA. The cold water protects the DNA by slowing down enzymes that can break it apart.
Why is cold ethanol used for DNA precipitation?
What is the purpose of ice cold ethanol addition?
The cold alcohol helps the DNA precipitate (solidify and appear) more quickly. Salty water helps the DNA precipitate (solidify and appear) when alcohol is added. The blender separates the cells from each other, so you now have a really thin cell soup.
What is the purpose of adding salt in DNA extraction?
By adding salt, we help neutralize the DNA charge and make the molecule less hydrophilic, meaning it becomes less soluble in water. The salt also helps to remove proteins that are bound to the DNA and to keep the proteins dissolved in the water.
What is the purpose of the ice cold 95% ethanol?
What is the purpose of the ice cold 95% ethanol? To precipitate the DNA from the filtrate.
Why did you need to keep the strawberry extract cold?
The chemical (detergent) process broke down the cell walls, cell membranes and nuclear membranes. The fruit mixture was cooled to stop the DNases released from the cytoplasm from destroying the cell’s DNA.
Why is chilling necessary for DNA precipitation?
Ice to chill the sample. Lower temperatures promote the flocculation of the nucleic acids so they form larger complexes that pellet under the centrifugal forces of a microcentrifuge.
Why ice cold isopropanol is used in DNA extraction?
The use of chilled IPA increases the rate of precipitation of DNA and allows it to flocculate and settle very easily and quickly. However, its recommended to use room Temperature Isopropanol because cold Isopropanol may increase precipitation of salt.
Why must DNA extraction take place at ice cold temperatures?
The students use cold ingredients to protect the DNA from DNases. Since reactions are slower at lower temperatures, using cold alcohol and other cold ingredients slows down the DNase reactions that break down DNA. Meat tenderizer also helps to protect the DNA.
Why must DNA extraction occur at ice cold temperatures?
The cold water protects the DNA by slowing down enzymes that can break it apart.
Why must DNA extraction take place in cold temperatures?
Temperature has a significant effect on the amount of DNA that can be extracted: the lower the temperature, the greater the yield of DNA. Hence, whenever possible, specimens should be kept at cold temperatures, preferably frozen.
Why is it important to keep DNA on ice?
1 Using ice-cold ethanol and ice-cold water increases the yield of DNA. Low temperatures protect the DNA by slowing down the activity of enzymes that could break it apart. A cell’s DNA is usually protected from such enzymes (DNases) by the nuclear membrane which is disrupted by adding detergent.
Does temperature affect DNA?
Indeed, it has been shown in biochemical ensemble measurements that temperature directly affects DNA structure by changing its persistence length. Besides such a direct effect on DNA structure, temperature might also influence the interactions between DNA and architectural proteins, and hence chromatin structure.
