LiSci DNA Extraction lab demo

Summary

This educational video demonstrates a DNA extraction process using strawberries. The teacher, wearing a lab apron and safety glasses, guides viewers through blending strawberries with salt, filtering the mixture, and adding soap solution. After resting, precise measurements of meat tenderizer are added, followed by the introduction of ice-cold isopropanol. The process concludes with the separation and observation of DNA, emphasizing careful handling and thorough cleanup, promoting a hands-on understanding of molecular biology.

Takeaways

• 🧪 The demonstration is a DNA extraction experiment using strawberries as the sample.
• 👩‍🔬 Safety precautions are emphasized, including wearing a lab apron and safety glasses.
• 🍓 A 10 mL strawberry solution is prepared with salt and blended, then filtered to remove chunks and seeds.
• 🌡️ The strawberry solution is gently stirred to ensure all ingredients are well mixed and no large particles remain.
• 🧴 A measured 1 mL of soap solution is added to the strawberry solution to facilitate DNA extraction.
• ⏳ The mixture is allowed to rest for 5 minutes to allow the DNA to interact with the soap solution.
• 📐 Accurate measurement of 0.09 grams of meat tenderizer is crucial for the next step of the process.
• 🥄 The meat tenderizer is carefully added to the DNA solution and stirred gently to avoid creating bubbles.
• 🧊 Ice-cold isopropanol is used to precipitate the DNA, requiring careful layering on top of the DNA solution.
• ⏱️ A waiting period of approximately 5 minutes is necessary for the DNA to precipitate at the interface of the solution and alcohol.
• 🔬 Gentle stirring at the interface can help in observing the DNA precipitate, which appears as a white cloudy material.
• 🧼 Cleanup is an essential part of the lab process, including disposing of the solution, washing equipment, and ensuring the lab station is left clean.

Q & A

What is the main purpose of the video?

The main purpose of the video is to demonstrate a DNA extraction process using strawberries.

Why is the teacher wearing a lab apron and safety glasses?

The teacher is wearing a lab apron and safety glasses to ensure safety during the laboratory procedure.

What is included in the strawberry solution used for DNA extraction?

The strawberry solution includes strawberries, salt, and has been blended together.

Why is the strawberry solution filtered through a strainer?

The strawberry solution is filtered to remove any large chunks, seeds, or other materials that are not part of the DNA extraction.

What is the role of the soap solution in the DNA extraction process?

The soap solution helps to break down the cell walls and release the DNA from the strawberries.

How much soap solution is added to the strawberry solution in the video?

1 milliliter of soap solution is added to the 10 milliliters of strawberry solution.

What is the purpose of letting the DNA solution rest for 5 minutes?

Letting the solution rest allows the soap to work on the cells and helps in the separation of DNA.

What is the role of meat tenderizer in the DNA extraction process?

The meat tenderizer, which contains enzymes, helps to further break down the proteins and isolate the DNA.

How much meat tenderizer is used in the process?

0.09 grams of meat tenderizer is used in the process.

Why is ice-cold isopropanol added to the DNA and soap solution in a test tube?

Ice-cold isopropanol is added to help precipitate the DNA, making it visible and easier to separate from the solution.

What is the final step in the DNA extraction process shown in the video?

The final step is to gently stir the border of the DNA and isopropanol layer to see the DNA precipitate and then clean up the lab station.

Outlines

00:00

🍓 DNA Extraction Preparation

The video script introduces a DNA extraction process using strawberries. The teacher demonstrates the initial steps, which include wearing a lab apron and safety glasses for protection. A 10 mL strawberry solution, mixed with salt in a blender, is collected using a syringe and filtered into a beaker to remove any chunks or seeds. The solution is stirred gently to ensure all components are well mixed. Subsequently, 1 mL of pre-mixed soap solution is added to the strawberry mixture, stirred gently to avoid creating bubbles, and left to rest for 5 minutes. During this rest period, students are instructed to measure 0.09 grams of meat tenderizer using a scale and a small plastic waybo, ensuring the mass of the waybo is not included in the measurement.

05:01

🧪 DNA Extraction Process

Following the rest period, 5 mL of the DNA and soap solution is transferred into a test tube using a syringe. The previously measured 0.09 grams of meat tenderizer is carefully added to the test tube, ensuring it does not stick to the sides, and is gently stirred to mix with the DNA solution. The next step involves obtaining a small amount of ice-cold isopropanol, which is poured gently on top of the DNA solution in the test tube to create a layer twice the volume of the DNA mixture. This is left to sit for 5 minutes to allow the DNA to separate. The script describes observing a white cloudy substance forming at the border between the DNA and alcohol layers, which can be gently stirred to encourage it to rise into the alcohol layer.

10:04

🧼 Cleanup and Lab Safety

After the DNA extraction and observation, the script emphasizes the importance of cleaning up the lab station. All leftover DNA and soap solution are disposed of in a labeled waste beaker, and all equipment such as syringes, strainers, and test tubes are thoroughly washed with soap and water. Special attention is given to cleaning the test tubes using a test tube scrubber to ensure no residue is left behind. The syringe and its plunger are also cleaned separately, and it is important to keep track of which plunger belongs to which syringe to avoid confusion. The lab bench should be left in the same or better condition than when the experiment began, with all materials properly cleaned and put away.

Keywords

💡DNA extraction

DNA extraction refers to the process of isolating DNA from cells or tissues. In the video, DNA extraction is the central theme, as the teacher demonstrates how to extract DNA from strawberries. This process is crucial for various biological and forensic applications, including genetic analysis and crime scene investigations.

💡Lab apron

A lab apron is a protective garment worn in a laboratory to prevent contamination and protect clothing. In the script, the teacher mentions wearing a lab apron, emphasizing the importance of safety precautions during the DNA extraction process.

💡Safety glasses

Safety glasses are protective eyewear designed to shield the eyes from potential hazards in a laboratory setting. The teacher in the video is wearing safety glasses, illustrating the need for personal protective equipment during scientific procedures.

💡Strawberry solution

The strawberry solution mentioned in the script is a mixture of strawberries, salt, and water that has been blended together. It serves as the source material for DNA extraction in the video, highlighting a common technique of using everyday materials for educational purposes.

💡Filtering

Filtering is the process of separating solids from liquids or gases by passing the mixture through a filter. In the context of the video, the teacher filters the strawberry solution to remove any large chunks, seeds, or other impurities that could interfere with the DNA extraction.

💡Soap solution

A soap solution is a mixture of soap and water, which in the video, is added to the strawberry solution to help in the DNA extraction process. The soap aids in breaking down cell membranes and facilitating the release of DNA.

💡Meat tenderizer

Meat tenderizer is a substance used to break down the proteins in meat, making it softer and more tender. In the script, meat tenderizer is used in the DNA extraction process to further break down the cell walls and release DNA.

💡Test tube

A test tube is a piece of laboratory glassware used as a vessel for conducting small-scale experiments. In the video, the teacher uses a test tube to contain the DNA and soap solution, as well as the meat tenderizer, for the DNA extraction process.

💡Isopropanol

Isopropanol, also known as rubbing alcohol, is an alcohol used for various purposes, including as a solvent in laboratories. In the video, ice-cold isopropanol is added to the DNA solution in the test tube to help precipitate the DNA, making it visible and easier to isolate.

💡Pipetting

Pipetting is the act of transferring liquids using a pipette, a tool commonly used in laboratories for precise measurements. The script describes the use of a pipette to accurately measure and add 1 ml of soap solution to the strawberry solution.

💡Scale

A scale in a laboratory context is used to measure the mass of substances accurately. The teacher in the video uses a scale to measure 0.09 grams of meat tenderizer, demonstrating the importance of precise measurements in scientific experiments.

💡Cleanup

Cleanup refers to the process of cleaning and organizing a workspace after an experiment or activity. The script concludes with instructions for cleaning up the lab station, emphasizing the importance of maintaining a clean and safe laboratory environment.

Highlights

Teacher demonstrates DNA extraction in a life science video.

Safety measures such as lab aprons and safety glasses are emphasized.

DNA is extracted from a strawberry solution mixed with salt in a blender.

Strawberry solution is filtered to remove chunks and seeds.

Soap solution is added to the strawberry solution to aid in DNA extraction.

Gentle stirring is recommended to avoid creating bubbles during mixing.

Meat tenderizer is measured precisely for the DNA extraction process.

A small metal scoopula is used for accurate measurement of meat tenderizer.

DNA and soap solution is transferred to a test tube for further processing.

Meat tenderizer is carefully added to the test tube to facilitate DNA separation.

Ice cold isopropanol is used to precipitate the DNA.

A layering technique is applied when adding isopropanol to the DNA solution.

Observation of the DNA-isopropanol interface reveals a white cloudy substance.

Gentle stirring at the interface helps in collecting the DNA.

Proper cleanup and disposal of materials post-experiment are demonstrated.

Syringe and test tube cleaning techniques are explained for lab safety.

Lab station should be left clean and organized after the experiment.

Transcripts

okay hi life science today we're going

to be doing a DNA extraction and this is

your teacher demo video before we begin

notice I've got my lab apron on I'm also

going to be put putting on my safety

glasses I wear glasses as well so I just

put them over top today I'm going to be

extracting DNA from Strawberry so the

first part of part of our procedure is

going to be collecting 10 mL of

strawberry solution with a 10ml syringe

this strawberry solution includes

strawberry but also some salt and it's

been mixed together in a

blender now I have 10 MLL of my

strawberry solution and because it might

be a little bit chunky I'm going to be

filtering it through a strainer into a

200 or 250 ml beaker

I can set this

aside and I'll use a glass stirring Rod

to just gently stir to make sure that my

strawberry solution all goes down into

the beaker and that I've caught any of

the big chunks or seeds or any of the

things that that I'm not going to be

extracting DNA from

once it's all

inside our next step is to add 1 ml of

soap

solution now the soap solution is

already mixed with water I have a a

pipet on top and if you look at the side

of the pipet you can see markings where

1 ml

begins so in order to obtain 1 ml of

soap Sol solution I squeeze my pipet put

it

inside the

beaker getting about approximately 1 ml

of soap

solution and then I add my 1 ml of soap

Solution by gently squeezing into my 10

m of strawberry

solution I'm going to stir that up with

the glass stirring Rod but I'm going to

do so gently so that I don't make too

many bubs

so now I have strawberries salt water

and a little bit of soap

inside um I'm going to swirl the

solution but now I need to let it rest

for about 5

minutes while your DNA solution is

sitting and resting with the soap inside

you're going to be measuring the amount

of meat tenderizer that you need um

we're going to be using a scale like

this one and a small plastic waybo now

one of the things you have to make sure

is that you are not including the mass

of the waybo in your massive meat

tenderizer so I'm going to put the wayo

onto the scale and make sure that I

press zero and ensure that it's zeroed

before I

begin I need

0.09 G of meat tenderizer and to get

that I'm going to use a small metal

scopula to put that onto the scale

that's already about

0.03

0.06 and I've gone a little bit too high

I don't want to add this back into the

Container because since it's been out

it's now contaminated so if you have a

little extra you can try taking a tiny

bit off

putting it

into the waist Beaker and now I'm at

exactly

0.09 gram this is what we're going to

add to our DNA solution when we do the

next

step after our DNA solution has been

resting we're now going to add 5 m

milliliters of this DNA and soap

solution into a test tube we'll use the

test tube

rack and we can use the same 10ml

syringe that we used last

time I now have 5 milliliters of my DNA

and soap solution and I'm going to

gently add it into the test tube right

down to the bottom just trying to be

careful not to create too many bubbles

our next step will be to add the meat

tenderizer that we just measured the

0.09

GS so to do that sort of tap it to the

edge of the waybo and we want to make

sure that the meat tenderizer doesn't

stick to the sides of our test tube so

I'm just going to very

carefully tap it

in and

then with a wooden stirring rod going to

very gently stir to make sure that the

meat tenderizer is all mixed with the

DNA our next step involves getting some

ice cold

isopropanol in class you're going to

have it in an ice bucket for me I've

already had it just straight out of the

freezer this this will be on the back

bench in class it is very cold um and

you're going to obtain about 10 to

milliliters or so in a very small 50 ml

Beaker it doesn't have to be exact for

this part you just need a very small

amount in the bottom of the

beer our final step is one where you're

going to have to be a little bit careful

we're going to pour the ice cold alcohol

on top of the DNA solution until we have

about twice as much alcohol or about

twice as much as what's in here so

you'll have this much again in alcohol

on

top in order to do this we don't want it

to mix too much we want it to form a

nice layer on top so I'm going to tilt

my DNA test tube I'm going to tilt my

cold isopropanol I'm just going to

gently pour down the side

until I have a

layer that's on top about as large as

the DNA layer below like

this we now need to let this sit for

about five minutes until we can see what

DNA comes

in let's take a look at how our DNA

sample has gone so here's our DNA sample

at the bottom this was our ice cold

isopropanol on the top and notice right

at the border of where the DNA and the

alcohol layer meet you see kind of like

some white cloudy stuff the last step

that you can do is with a stir Rod is

just kind of stir very

gently at the border to see if you can

get some of that that white almost

cloudy looking material to kind of come

up into the alcohol

layer and we see a tiny a little bit

kind of coming up into the layer

there all right now that you've

extracted your DNA and you've taken some

observations we got to clean up so your

DNA solution this is all going to go

into a labeled waist Beaker that's next

to the sink so you can just tip that

into the waist

Beaker um any leftover DNA and soap

solution that was in your Beaker will

also go into the

speaker and then you're going to be

cleaning up your

syringe your

strainer and your test tube so let's go

over to the

sink make sure that you wash everything

with soap and water and when you wash

your test tube please use use a little

test tube scrubby to get all the way

inside okay when you clean your test

tube um just give it a little rinse with

water

first then you're going to use the

scrubby get a little bit of soap

Solution on and just scrub inside the

test tube all the way down to the

bottom okay and then give it a really

good rinse make sure there isn't any

soap Left Behind inside the test tube

and when you dry a test

tube it just goes upside down on the

drying rack that's the signal that it's

now washed and cleaned ready to go for

the next student when it comes time to

clean your syringe notice that the

syringe and plunger can come out so that

you can actually clean inside the

syringe you'll have a little test tube

scrubby you can use that to get

inside and then just make sure that you

flush the tip through with plenty of

water and that it's flowing

freely this can stay at your lab bench

but make sure that you don't mix up

which plunger goes with which syringe

because they tend to fit pretty

exactly your lab bench should look

exactly the way it did when you came in

if not better so make sure that all of

your your materials are cleaned up and

set back before you leave the lab

station thanks everyone