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Using DNA to Identify People 

MIT BLOSSOMS
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This lesson focuses on the molecular biology technique of DNA fingerprinting: what it is, how it works, and how the data from these experiments are used for paternity testing and forensics? DNA can be used to tell people apart because humans differ from each other based on either their DNA sequences or the lengths of repeated regions of DNA. Length differences are typically used in forensics and paternity testing. The technique of gel electrophoresis separates DNA by size, thus allowing people to be identified based on analyzing the lengths of their DNA. We discuss how gel electrophoresis works, and lab footage is shown of this technique being performed in real time. Students then analyze results from these experiments and work on case examples using DNA to match babies to parents and crime scene evidence to suspects. In terms of prerequisite knowledge, it would be ideal if students already have learned that DNA is the genetic material, and that DNA is made up of As, Ts, Gs, and Cs. It also would help if students already know that each human has two versions of every piece of DNA in their genome, one from mom and one from dad. Necessary supplies for this lesson include only paper and writing utensils, and the ability to print out or display the provided handouts. The lesson will take about one class period, with roughly 30 minutes of footage and 30 minutes of activities. At the end of the lesson, an optional video tour of the Cambridge Police Department’s Identification Lab is provided, giving students an opportunity to see the equipment used in crime labs to isolate both real fingerprints and DNA for DNA fingerprint analysis, from evidence found at crime scenes.
Watch optional video (blossoms.mit.edu/videos/files/... Visit to Police Identification Lab in Cambridge, MA to see how DNA is extracted from evidence at crime scenes.
For more information:
‪blossoms.mit.edu/videos/lesson...

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16 июл 2024

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Комментарии : 80   
@SallyBR
@SallyBR 2 года назад
Honestly, I don't know WHO could give a thumbs down to your presentation. Must be some really sick and unhappy human beings. I hope you don't let that bother you. Thank you for a beautiful, clear and concise presentation
@joehanshe8774
@joehanshe8774 7 лет назад
An excellent representation of what actually happens in the laboratory of a DNA analyst.
@MuhammadUmar-qx8di
@MuhammadUmar-qx8di 4 года назад
This is a wonderfully laid out presentation; thank you so much.
@cheoignatius960
@cheoignatius960 5 лет назад
I,m so clarified after watching this presentation
@ChristineSabella
@ChristineSabella 5 лет назад
just realized, this was uploaded on my birthday. best birthday present.
@shreyadeshmukh7197
@shreyadeshmukh7197 5 лет назад
Beautifully explained👌
@absiddique8247
@absiddique8247 4 года назад
elaborately and nicely explained. well done!
@joeclarke9782
@joeclarke9782 4 года назад
Excellent show and tell.
@ghideygebrhanes3709
@ghideygebrhanes3709 4 года назад
Informative video lecture
@sadeklab
@sadeklab 5 лет назад
Simple, Efficient , Excellent I like your sound
@sanjaykumarmallick7414
@sanjaykumarmallick7414 6 лет назад
I'm literally crying....ur video made my concepts so clear..may God bless you the finest things in this world
@ChristineSabella
@ChristineSabella 5 лет назад
sameee
@OZTutoh
@OZTutoh 4 года назад
I agree. God bless you.
@peshawarzalmi7781
@peshawarzalmi7781 4 года назад
Thank you very much for this informative presantion
@sarathvijayananda769
@sarathvijayananda769 Год назад
Thank you very much for your clear explanation.
@pauldiaz4273
@pauldiaz4273 6 лет назад
Excellent!!
@doctordnatyping9424
@doctordnatyping9424 6 лет назад
Excellent video
@oliviapereira364
@oliviapereira364 3 года назад
Thank you so much for the explanation! In forensics, how can one sequence DNA from sperm and compare the result to a suspect if gametic cells have a different DNA than somatic cells (due to crossing over of gametic cells)? How can one know what to look for if that's not the same sequence?
@user-fd6km2rw8z
@user-fd6km2rw8z 5 лет назад
thank you so much
@chandrakritimaisnam3463
@chandrakritimaisnam3463 5 лет назад
Nice video keep up the good work
@ameenali313
@ameenali313 4 года назад
very nice presentation
@omsingharjit
@omsingharjit 4 года назад
12:44 How it's done in dna mesh because it's would not be same as doing in papers?
@europhile2658
@europhile2658 Год назад
excellent presentation
@sampathit
@sampathit 5 лет назад
Great video
@ramaraju5882
@ramaraju5882 5 лет назад
Nice and good video
@abelincolnparth
@abelincolnparth 5 лет назад
It would be nice to know what specific kinds of products you buy in terms of repeats that are available. Do you have any links to share from the manufacture? You talk about a sequence from chromosome 4, but you don't say that you isolated chromosome 4 for analysis.
@joycechi9697
@joycechi9697 2 года назад
thank you megan my queen 🙏🙏
@nollypelobueno7589
@nollypelobueno7589 3 года назад
Thanks.nice explaine.i'm enjoy watch vidio
@Uther001ful
@Uther001ful 2 года назад
How do you select just the section of the dna that you want to test?
@7071t6
@7071t6 6 лет назад
So she either has 12 separate different DNA samples or 12 of the same DNA sequence from different people ?at the 30:25 mark which is in the Matrix GEL medium ?
@suyashathavale7687
@suyashathavale7687 6 лет назад
I liked the way you carried this viedio
@7071t6
@7071t6 6 лет назад
The answer to the first question is that the chemicals would be the same, but in different orders ie: if it was the DNA which represents the chromosomes for your eyes, then its would look the same, but with various differences like i mentioned the chemicals with in the chromosomes are different order ? Also as far as identical twins, do they have the same finger prints over their lifetime ? Also has there ever been twins where one is a male and the other is a female ? If so then the identical twins will have different DNA, due to the chromosomes are different from male to female ?
@ChristineSabella
@ChristineSabella 5 лет назад
that was amazingg
@bekegift6886
@bekegift6886 Год назад
Good explanation ❤❤❤❤
@7071t6
@7071t6 6 лет назад
Bib mistake when loading the DNA even though she used a new tip on the tube which takes the DNA out of the storage tube, it will mix with the inside of the gathering tube she uses ? After all its taken out by air, every time she touches the end or pushes the button its sucks out the DNA sample, so if the suction is to high it will remove DNA sample and thus contaminate a new sample, even though its the same DNA sample,what if a person uses it on a different test >?
@7071t6
@7071t6 6 лет назад
Also she said different people @ 30:25 - 6 / different samples of different peoples DNA when it started off having more copies of the same DNA sample to test from the PCR machine ??
@paulmiller184
@paulmiller184 2 года назад
I don't see how the material gets from the swab to show as the dark bands we see as the final evidence. There's one or more steps missing. Must be on a different presentation...
@TheShernavaz
@TheShernavaz 6 лет назад
What about donor's blood in recipient?
@thecat8905
@thecat8905 2 года назад
Important question(s)…. 1.) Is it physically possible to change someone’s DNA with a shot to the spine..? (CRISPR) 2.) Is it possible to hack in to a persons DNA Results and change it to match someone else’s family if they have the DNA from a different mother? This question is very important to me and Thank you .
@divyaratnawat1561
@divyaratnawat1561 6 лет назад
nice video
@7071t6
@7071t6 6 лет назад
I wonder how much is the electron microscope worth that they use and also the chemical used to separate the DNA into various individual DNA strands and how much of our DNa is clear and matched up ie: they know every single chromosome and what it does in the human body and its chemical signature and what are the main chemicals which make people have diseases and what the chemical signature is for each chromosome for those specific diseases ? Which main diseases have they mapped worldwide, like say how the human body is copping with the common cold for example ? also what are the main chemicals in each DNA as the main 5 or 10 that everyone has in each DNA chromosome sample ?
@7071t6
@7071t6 6 лет назад
What si that liquid used or matrix medium, like i mentioned in my lower comment, if you can work out what chemical or medium used can change the time frame of larger DNA samples and smaller DNA samples then you can change the outcome of any DNA test done ? Also if your the chemical company that provides this chemical used in the DNA Matrix Positive and negative DNA matrix testing you would be on a winner. :) Patent it and then charge what ever you like, especially in forensic and Paternity cases ?
@appalac9136
@appalac9136 3 года назад
great
@khalidjanabi
@khalidjanabi 4 года назад
Well done .. a crystal clear way of illustration. Thank you very much
@7071t6
@7071t6 6 лет назад
A positive medium would be used and then the larger DNA would take longer to get through the gel matrix and the smaller DNa would move faster through the matrix medium and then you could manipulate the medium to make them move in different speeds as long as those in charge of the DNA test dont know you have changed the matrix medium,yet you have put on paper that the medium used in the matrix is so and so chemical which is used in all gel the dna tests ?
@7071t6
@7071t6 6 лет назад
So basically when she started the test with the GEL Medium and or Matrix, she should have told everyone that its a paternity test and not lead everyone into thinking we are going to really see real DNA or chromosomes attached to a DNa strand ?
@7071t6
@7071t6 6 лет назад
@ 26:30 they are not your parents because the lengths of the DNA do not match with your sample, your mom has passed her DNA and genes to you but the sample of DNA in this test shows that the DADS DNA has not transferred to you otherwise you would have the same length DNA strand of chromosomes as part of this test ? Thats why in paternity test you always use the right sequencing of the DNA which always tells you if the DAD or MUM has pasted on his or her genes and chromosomes in the DNA sequencing etc. cheers and good luck in the rest of the test . :)
@rosaravelo3709
@rosaravelo3709 5 лет назад
Very well explain, you are good and the video is great, just one question, if our DNA is unique and it is our fingerprint ,in a paternity test where all sites tested match, why the probability of paternity never reach 100? I have seen that some reaches 99.99999 others 99.99997 etc but never 100
@brittniep9219
@brittniep9219 3 года назад
It is based on statistics. For example, with STR, the U.S. uses 13 loci. This puts it in the range of 1/100s of trillions, but it can never rule it out completely.
@mas-azlindah-ayu1622
@mas-azlindah-ayu1622 3 года назад
She is gooooooooooooood
@7071t6
@7071t6 6 лет назад
the main reason why the coping is done, is that you need to run the tests to confirm or deny the results and also to keep samples of the copies for future reference and storage as well and should other LABS need to do the same tests to confirm or rebut your tests ? Also THE USA and some other countries share the DNA samples to get a good idea of who is out there for example the president of the "USA each one is different thus security measures will be different for each president?f
@7071t6
@7071t6 6 лет назад
So basically you can't use DNA on Twins in a criminal case, because you can't tell which one did it right or wrong ?
@MikeCCO
@MikeCCO 3 года назад
2 True. or maybe its 2 False.
@brittniep9219
@brittniep9219 3 года назад
No, you can, but it is looking at the entire genome and therefore is very expensive and uncommon. Usually other ways are used, e.g. one twin has lost teeth/dentition or broken bones, etc.
@moonsevinci88
@moonsevinci88 11 месяцев назад
​@@brittniep9219can you explain more please
@onatovonatovic526
@onatovonatovic526 4 года назад
I don't understand how they select specific sites of DNA for analyzing.
@brittniep9219
@brittniep9219 3 года назад
Do you mean the process or decision?
@onatovonatovic526
@onatovonatovic526 3 года назад
@@brittniep9219 snps selection decision. are they scan all the genome and compare with others?
@deathslayer1411
@deathslayer1411 3 года назад
Thank you for the video
@evansongicho3296
@evansongicho3296 3 года назад
wow! that presentation was EXELLENT
@hidayatullah6740
@hidayatullah6740 6 лет назад
Mam you are unique and I am interested in research Lab please give me opportunity .......
@hidayatullah6740
@hidayatullah6740 6 лет назад
For MS in Human Molecular Genetics please...
@sarahbrown9293
@sarahbrown9293 10 месяцев назад
🤔
@7071t6
@7071t6 6 лет назад
To enter Hi security security agency around the world, because your DNA is the only DNA which will open up a door to enter or in criminal cases to prove or disprove why your DNA is found in blood or body fluids or substance left on a dead body or paternity cases which needs clarification ?
@nyangakalupala721
@nyangakalupala721 3 года назад
good job
@chandrakritimaisnam3463
@chandrakritimaisnam3463 5 лет назад
. 1%
@sarahbrown9293
@sarahbrown9293 10 месяцев назад
the teacher assumes that the student knows what she's talking about without pointing to. She leaves the exercises with insufficient context to come to conclusions... she never took teaching classes
@7071t6
@7071t6 6 лет назад
Now that we have the DNA mapped, just imagine if you use that technology to make a perfect person with no Problems, which i believe is impossible and my reason is that over millions of years or at least in the last 150,000 years our DNA has changed to the point that curtain chromosomes and markers for various diseases would interact chemically and thus make it useless to remove a chromosome that controls say the color of your eyes for example and changing them to light green for example, you would need to know which chemicals of the chromosome is working with which other chromosome in order to change the outcome, i think we are at least 50 years away from making the Orwells prediction of 1984 ? Yet we have had the lower classes doing all the crap work now since the first job, ie: prostitution and also SALES or bartering,which are the two oldests jobs known and nothing has changed since man first walked the earth other than a hunter and the gather which used to be the younger women and the man were the hunters ?
@drams8710
@drams8710 5 лет назад
All chromosomes come from both parents contain same genes...then how one parents DNA is bigger than other...
@brittniep9219
@brittniep9219 3 года назад
You get one from each parent. Our genetics are all slightly unique so one parent has mutations the other parent may not have.
@rachealmichealson9654
@rachealmichealson9654 Месяц назад
Thank you for this presentation ❤
@davemckay4359
@davemckay4359 4 года назад
Here's a real question: how mush dna is similar in each person, that they analyze in forensic cases?
@brittniep9219
@brittniep9219 3 года назад
It depends on the test but typically the more discriminating, the better. Which is why in STR (CODIS) they use 13 STR to determine a "match." The likelihood is 1/100s of trillions then.
@hyperactive99999
@hyperactive99999 6 лет назад
We will show them Our signs in the horizons, and within themselves, until it becomes clear to them that this is the truth. Is it not enough that your Lord is witness over all things? quran 41_53
@victoriar9728
@victoriar9728 3 года назад
3Billion? how did you count it? of course we are 99.9% similar DNA because we all came from ADAM and EVE in the beginning! so really humans belong to only one race. :)
@Dragon34th
@Dragon34th 4 года назад
Lol line 5 is your cat 🙀 👈🤣dna then your mum & dad dna. I think your cat is going to jail because CGAT reads cat 🤔👌lol 😂
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