Health Huddle EP6: DNA In Movies - Can You Get DNA From A Strand Of Hair?

welcome to the sixth episode of

healthpuddle

where we discuss interesting topics

about healthcare

wellness and genetics everyone is at 8pm

so

um today's discussion um

as you already know is about dna in

movies

okay um so dna in movies is basically

a series that we're doing uh where we

want to talk about how

genetics are portrayed in films and tv

shows

and also to debunk the science behind

how they actually work

or you know if um they're actually

exaggerated

you know so we wanna tell you guys uh

the truth behind the science

of all these uh movie dna portrayal

okay and today's main topic that we are

gonna talk about

is our dna sampling methods that are

shown

in movies and tv shows so welcome

everyone and thanks for tuning in

and i am jane from advanced health and

um this is lynette

also from everyone's health hi i am

so we'll be your host for today and

you know um if you have any questions

about dna

or dna sampling you know feel free to

leave your comments below

and join us in this discussion okay so

um before we begin maybe we can tell

them

a little bit about what is dna sampling

yeah sure so um actually the ena

sampling is

the way that how we collect the dna from

uh certain dna samples that we can

collect from

like uh by sobbing like clubbing for our

cheeks

or from saliva blood hair

nails bones cement urine

pieces tissue cells to determine the dna

profile

of a person of an individual so sampling

is already

so sampling is basically the method you

use

to get somebody's in nana

yep okay so um i think

in movies there's a lot of uh

dna sampling methods that we commonly

see um

and the main purpose they use dna

sampling for is either one for paternity

testing like when they want to find out

if

this guy is the baby's father you know

stuff like that

yeah the drama drama yeah all the other

hokkien drama you know they like to do

all this

a second one would be to do forensic

testing when they want to identify a

victim

or criminal with like skin

tissue or like with hair with blood

so these are the two common

dna sampling reasons in all these movies

so let's talk about the methods in

specific

so like i mentioned one of it just now

was hair

so we know this um dna sampling is one

of the dna sampling methods

is to use your hair but how do you

actually get

dna from from your hair

okay so actually it's quite common when

we watch

movie or drama they always like plug

someone's hair

yeah it's very common when you can see

in drama and movies but actually

for hair we have we can divide it into

two parts like

we have shaft and also roots so

actually um from both also we can get

the dna but with different technique

and um for yeah for your hair but for

your hair dna testing to be very

successful we must have the follicles

uh to attach that at your hair means you

might have to root

also and then yes

and then for the shaft like your hair

when you cut it

it's not entirely useless but uh they

are

fine for every like every specific type

of

of the test there is a specific test up

for the

cut hair or the shaft is known as mt dna

test which is a mitochondrial dna

so this technique actually is used to

determine whether the two persons share

the same maternal line or not

[Music]

so this is the difference but actually

if you really want to get a very very

uh successful dna test it's better to

have the roots

with the roots the whole whole roots and

the

sharp the whole thing and then we

actually if

one only it's not possible to get

accurate

oh so so you cannot just take like

one strand like that how much hair do

you have

actually we need at least six to ten

strengths

to get the very very successful dna test

yeah okay a bit hard right one yes to

get 10 strength from somebody discreetly

you need to pluck their hair and

strength

i think the person already knows he's

like why are you my hand

okay i think a lot of people kind of

know

that you know some may sound this may be

exaggerated but a lot of us think that

you know you can only use the root with

the follicles

you know we thought that the bottom one

all you cannot use

so you actually can use one we can use

it but

only for specific technique so

is is hair sampling actually commonly

used

uh it's not commonly used because uh

we cannot make sure that every hair

strands we have the

follicles with it and also um

for the freshly packed hairs maybe uh

you can we can get a better result

but if for the old one we need

yeah the old one we need to opt to use

the more advanced uh

method testing method but it will it

will cost

more means higher cost for that so it's

not

very common so if let's say like their

hair

is like damaged or like they died

already or something

then you know would it affect the

dna test also um

if for the the next one it possibly will

affect the result yeah because

as i as we mentioned if the hair the

older hair

we might need a very very advanced

testing method

how is the accuracy i'm not sure but uh

it definitely

will affect the result i see

okay so now we know our hair sampling

is possible you know but it's definitely

not as easy as those token drama where

they're just going pluck

one one straight okay then it's enough

you need

six to ten strands okay yeah

i i guess it's not a very efficient way

to do sampling last since

you know it's a bit hard and very

painful

to get the hairs as well okay

so let's talk about the next sampling

method

um i used cups or used

tissue paper so the scenario is

also i think some hokkien drama or you

know all these

dramas where you know they will just go

to the rubbish bin and pick up a

cup that the girl used before then

they're going to send it to the lab

then they can get the dna result so

how do you actually get dna from

fiber for example okay

for um if for the this scenario the

carbon tissue paper all that

actually before we talk about saliva

there's another

thing that uh that we we call it as

touch dna

means that when you

when you just hold a card or you just

use a tissue

anything touch or when you touch

something

there's definitely a some small amount

of dna

attached to it because uh your hand

probably will sweat

or maybe you will have some uh skins the

the

what we call it the dried skin or the

tricks of the skin tissue over there so

there's a small amount of dna

on it so actually for that

it's already enough to get a dna profile

ready

of a person so for the even for the

cup some girls they are using uh the

lipsticks and then when they drink

there's a mark over there yeah yeah

yeah so actually that also can we can we

also

can get the dna from that

so how do you actually you know um

get dna from from sliver

you know because you know in those

scenarios for example that they show in

movies

it's like just very little bit so is it

enough or

in reality do you actually need more

volume

uh it actually depends on what test you

are taking but if

we talk about crime scene means that uh

if for crime scene we cannot there's a

lot of possibility we cannot uh

we cannot expect that a we can get a

really

good amount of the saliva

or the other i mean other

yeah we cannot predict we cannot expect

we can get

a big amount because whatever left we

left

so for that also we actually can get the

dna profile but we need more evidence

to show to to support the data that we

get

but if you uh if

aside from this crime scene if you are

doing some kind of dna test like protein

tests or some help screening tests

something like that then probably we

need a more

amount of the more big volume among one

big volume of the saliva

so that we can get more dna

in it so because

unless it's for forensic um

usually you would need more than just

one tissue paper

yeah because if you are just only giving

doing a test

means the the person only will receive

one of your sample

only survivor sample so whatever they

will get just only from the survivor

center but if

crimes there's a lot of possibility so

definitely they will get many many

different different samples

maybe it's from you or other person but

if

we are only doing certain types of tests

then probably

we need more amounts so that we can get

more dna extracted and then

we can get a more uh accurate result for

them

so if let's say for like wellness

testing or like

paternity testing you know and i just

bring you

one tissue paper like that you know with

the dna it's

usually not enough it's not enough for

that

so it is this uh of course i think

normal people

unless you're very desperate you won't

go and sample

using tissue paper or capsule you know

uh but

if for example in the case of sliver

sampling is this a very common kind of

practice

in general labs for dna tests

yeah it's a quite a common uh common

technique common sampling method for the

normal dna test that yeah because

we actually we can get a lot of dna from

our

saliva and also our cheeks mostly the

buccal swab means the

the cheek swap and also survivor these

two types method is the most common one

okay okay so

um we've gone through two sampling

methods so far one is hair

and now for use cups or tissue paper

also we're talking about sliver sampling

so from now we know that um

you know small volume is possible but

usually only for labs with

the technology to be able to process

that

for forensic purposes you know but for

general labs is generally not enough

and you definitely need higher volume of

sample for those so let's move on to the

next sampling method

so okay another scenario i think

um this one also sometimes we see like

some some shows

some movies where they just take one

drop of blood

uh like maybe this person accidentally

had a paper cut

then they go and take the the blood drop

on the paper

and they go and do the test so is this

possible

okay so in for this scenario actually

blood there is two types of the sampling

method

one is in liquid form when the blood is

imposed

and another one is uh probably the dry

blood stem

so um for the liquid one there's there's

two ways that for the

for the liquid one usually uh they will

pick

on through the gauze pad or the creams

the sterile cotton cloth

and then it should be dried thoroughly

and then

in refrigerator and overflow or frozen

need

then only we'll send it to the

laboratory but we have to send it

as soon as possible i don't it's better

not to delay uh 48 hours

because uh probably if if there's any

delay

or uh from 48 hours then

a result might not very accurately or

maybe the blood is

uh we cannot use that samples already

yeah so this is the liquid and for the

drip stain

usually it will drop on the cloth or

maybe on some solid object then

for blood flow for the cor um if the

blood is dropped on the cloth so we have

to wrap it in the cream paper and then

we'll place it in the brown paper bag

and or a box then we have to seal it and

label it but

do not remove the stain from the cloth

you you have just what you need to do is

just cut off the cloth and then just

send the whole piece

to the left but don't uh remove the

stain from that

because the the left there you have a

certain process

they'll use some chemicals to remove the

steam from the core

and if for the solid object it's a small

one also the same you have to

cover it with some paper bag or

something and then send it to the lab

but for the big object some object is

not possible to like send the whole

thing to the lab right

so uh you can use the clean

knife the already there's already a wash

properly

and then we can scrape it off scrap the

stain

and then scrub it onto a paper

and then but the paper must have to

must have to uh i mean you you the paper

we can

fold it up the the paper that we can

fold it and also we can place it in this

envelope

so the main point is we have to use the

freshly washed

and also dried uh knife nut

yeah but do not mix the dried stain

together

i mean you have to make it separately

because you're not sure right whether

is it someone's blood something like

that yeah

so so does that mean that you know

if you use this kind of method like you

know you scrape it off uh for example

like the wall

you know or yeah you take from a dried

uh

gauze or something doesn't mean you

don't actually need a lot of blood

for it yeah because um

for as i mentioned just now from the

crime scene there's a lot of

possibilities so

sometimes we are not able to get a lot

of amount of blood

so what whatever left you left so we

only can get whatever is left

over there and then but then we are

still able to

uh get the dna profile because

uh in the forensic lab which actually

are very very they have very very

high tech and also advanced uh technique

and also uh

we call it equipments to uh the high

sensitivity

high sensitivity technology like to get

the dna profile

from the small amount of the samples

but then we still need

a lot of evidence to prove that a this

bird is belongs to this person

yeah so there's a lot of possibilities

from the crime scene

yes so even if small amount we can we

can get dna

from there but we need more evidence and

also more

investigation to make sure that a the

result that we get is accurate one

is beyond so this person or do not

belong to this person

so so if for example let's say um

there's this blood dna sam there's this

blood sample okay

um but then let's say the blood is mixed

you know it's not just one person's

blood

so when when you run the test in the lab

um would the lab be able to know that

it actually belongs to how many people

um actually for if for lifetime the

very very old time maybe we only can

know that

this word is belongs to someone

but then for now the technology is

more and more advanced we can know that

the dna mixture is from

certain person but then there's three

treatments factors that we have to

determine

the compressive complexity of the dna

mixture

because actually if the the dna

is mixed together then we need some time

and we need a lot of time to determine

uh

this dna is belong to which persons

so there's three main factors that we

have to

avail one is how many people contribute

to the dna to the mixture

so if there's more contribution so

means that there's more complexity so

it's more difficult for us to determine

uh who belongs the the dna belongs to

which individual okay so

the second one is how much of dna

did each person contribute means that

uh the dna might we might have a lot of

dna samples over there

but one or several people they might

have contributed a little bit dna only

so if there's a lower amount there's

more capacity to get

the the long capacity and then it's more

difficult to

get the result that what resulted what

we want

and then for the third one how

degradable is a dna means that

because dna degrades over time and

also when it exposes exposed to a

certain element it might have

contamination or degrade so it also

increase the complexity

for us to determine

the dna belongs to which person

so if since you said dna degrades over

time you know and it might get

contaminated

does it mean that if let's say the

sample uh

actually um degraded a lot you know and

it's

also contaminated um with other

substances um for normal labs

uh that doesn't have such high

technology they would not be able to

identify or be able to um

run the test or to

identify the dna profile

yes if if for degraded dna or the

contamin content dna probably i think

most of the labs are not able to

uh get the accurate result from that

because if your dna is already degrade

the machine they can't detect your dna

so

your result might be false yeah so

unless it's like

your super your country's most high-tech

lab for forensic

you know then you won't be able to use

that sample anymore

yeah because the dna is really great we

can't get anything from there

okay so i guess you know since

most of the time when we see all these

uh sampling methods it's usually for

forensics

let's just assume that you know in csi

they actually get to

send it to the most attack in the u.s so

you know that's why it works you know

but um

yeah so i guess if any of us ever want

to do a paternity test

discretely uh we need to remember that

um blood sample um need to be

processed really soon and that you know

there's chance that you will degrade

also

yeah okay so

okay so that's our three sampling

methods that we've covered so far

and i think now uh the last sampling

method that we're gonna talk about today

which i think is only used

in tv shows for crime scenes

is a skin tissue so the scenario is

usually sometimes they will find like

from the

victim's fingernail you know that

there are some skin flicks like inside

or something

you know then they will go and do the

test and then they'll find out oh this

is the murderer you know

she scratched this person when he was

killing her you know stuff like that

so um how do you actually

uh get dna from skin tissue and you know

is it accurate

okay so uh for the flakes of skin and

also the

skin skin tissue everything actually as

what i mentioned before

it also depends on the crime scene how

like how much of the volume left there

even a little even a little volume also

we can get the dna profile

from that so it is possible to get the

dna

from there and there's certain data

of course they need to undergo a certain

uh process that like

after the sample have been sent to the

lab they

might they have to go through dna

screening and then they have to purify

the dna

and then they will have to do validation

everything go through

a series of process then only we will

get a really

good result for that good then it has a

read up for that

yeah it is possible

it's possible okay but but then you know

um when you talk about skin tissue

because nowadays there's a lot of

different

skincare products like cosmetic product

so if

let's say for example um

if the owner of the skin tissue

had cosmetic products on at that time

you know so that means the skin flakes

also has

some component of the cosmetic product

mixed with it

so would it actually affect the dna

result

okay so for this part actually it

depends on the technique

because as as i mentioned when we

have already collected the sample we

send it to that we have to go through

dna extraction

and then we have a dna purification

steps in it in the process so

after we have purified after we have

extracted the dna

and then we have purified it so uh it

will be a very

good quality of we'll get a very good

quality of dna if the technique is

correct it's right so we have to do the

validation test as well

to know that a whether this dna is it

pure or is it a very good quality dna

so actually the cosmetic everything

does not affect the dna

purity unless the when

in between the process there is

something wrong then

probably it will affect the result but

if

the technique is correct the technician

is

i mean they did everything correctly

they follow

the protocol everything and the

purification

step is uh very i mean

yeah if the perfect purification steps

is

right so it the cosmetic or anything it

won't

really affect the dna rings now okay

so at least uh it's assuring to know

that

you know you won't really identify the

wrong

criminal for example in the case of

you know crime scene when they discover

skin flakes

so okay yeah i guess in general all

these movies

actually do portray the sampling methods

um somewhat quite accurately especially

for

like those crime scene movies right

yeah actually what uh what the movies or

drama they portray actually it's quite

true it's just that maybe it's not as

easy as what you see

through the television because the way

they go because they cannot show very

detail

they only can show like oh i i i just uh

going through this step this step

but it's not in detail so it's quite

accurate

but there's more details inside that

more process and also details that we

need to

really uh we need to really

handle uh when we collect the samples

and also process the sample

so actually what we what we show in the

drama

a movie is quite uh accurate i try to

say that

yeah that's behind it maybe it's not

that easy right that's what

show it like they skip too much detail

in between

yeah they just skipped the details

because if you really want to show the

videos quite long already

and take i think can pick it up for one

or two before

oh yeah yeah make sense make sense

for that okay so i guess

um that would be all for our discussion

for today

so you know if any of you who are

watching if you have any questions

about dna sampling or you know just

anything

about dna in general do leave your

questions in the comments below

thanks lynette for sharing your

knowledge uh i guess um

a lot of us has always have the idea

that oh all these movies

are shifted you know they just use the

concept but

it's actually not not possible to do

like this

but i guess from today's discussion we

know that it's actually possible

but you will need high technology

skill technicians yes and also probably

a lot more time

yeah yeah more evidence

more investigation to make sure that the

result is accurate

i guess you know if anyone ever you know

want to find out if you are your

mother's daughter

you know um just go

and do the test with your mother like

instead of you know her hair

yeah you need to plug 10 strands uh

it's too difficult correct you also

yeah um movie sampling methods

is for special case only so

yeah we'll just go for the um easier

more efficient methods

at the labs all right so there are no

other questions

then uh we officially wrap up today's

episode

so thank you once again for joining us

on the sixth episode of health huddle uh

do share

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so we'll see you in two weeks

and yeah thanks for joining us and have

a good evening

bye thank you everyone thank you jane

bye

thanks nina bye

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