Pregnancy test


welcome back guys in this video tutorial

we'll be talking about the pregnancy

test geet okay so how the pregnancy test

kit actually works that we use in home

to test pregnancy now normally the

pregnancy test case that is used for

mammals you can test it for actually it

is made for a human being except for

that it can be tested for other mammals

because the foundation principle on

which the pregnancy test kit actually

works is the release of a hormone with

the urine and that hormone is termed as

human chorionic gonadotropin human

chorionic gonadotropin so this is the

hormone it is termed as HCG now the

presence of HCG hormone in urine

indicates conformation in pregnancy now

normally what happens during the process

of development of an embryo what happens

during the after the fertilization is

done there are sequential stages egg is

being made then sperm is getting

inserted and fertilizing the egg now

once the fertilization is done they

against now producing this I goat it

should be implanted into the endometrium

now once the placenta is being implanted

in that endo metrium in the wall of this

all of this in demetria more uterus wall

in that time after the implantation of

that egg onto the wall of uterus it

starts secreting HCG hormone now in that

particular time the HCG hormone if there

are different variety of HCG hormone

alpha ECG beta HCG and different

versions that the presence of HCG in

blood is determined from the first day

of the implantation but after the second

day of implantation normally after the

second day of implantation the

concentration of HCG start to increase

in urine right so it's very easy to test

urine out you don't need to take blood

out or anything you can do it in the

home so normally there are kit Abell

available now that

is designed to detect the presence of

HCG hormone in urine normally the

concentration of HCG is highest in urine

one is the concentrated form which is

always in the morning the first

urination concentration of all the

proteins and hormones and other

materials are their highest in the union

that's why all the urine tests are works

in the morning so in that case need to

take it and put it into the stripe there

is a region in the strip of those heat

and then capillary action will draw the

urine out and then ultimately there are

three important sections in that strip

that is helping to determine whether it

is suggesting the proposed ative result

or the negative result if we draw the

test kit in this case it will look

something like this so I am drawing this

kit schematically normally two important

situations are there one is the test is

positive one other one is negative so

we'll be seeing both of the situations

so there is a place for placing that

earring so placing the sample so sample

in in this place right so sample in this

region after that there are three

important section one is this reaction

center or our region another region for

example let's say the test send Center

so let's say this is the test center and

this is the control and in this case

also reaction test and control these are

the three different regions placed in

this strip actually four one is the

place for adding the sample another

three region one is for reaction T's for

tests is for control

so let me write R for here reaction T

for test C for control now what we are

doing in this case in the our region in

the our region what is there we actually

use antibody we add antibody into the

strip to detect the presence of hormone

so normally antibody is produced against

a CG in Mouse so those antibodies

our turn - aunty HCG antibody so we are

having many anti HCG antibodies now this

aunty HCG antibody can bind with HCG or

human chorionic gonadotropin so if I

draw the antibody it will look like this

right it can bind with HCG hormone and

actually a special region of its CG this

interaction is possible right and this

antibody FC region is designed in Mouse


so it's designed in normally in Mouse so

this is the structure of this antibodies

that are placed in the our region of the

strip now the second thing is T the

antibody that is present in T region of

the strip is also an THC G antibody and

is having the capability of binding with

HCG but but there is having slight

difference the antibodies that are

present in the our region are having

enzymes attached with it so this is the

type of antibody that represent in our

but in T region though we are having an

t HCG antibody these are also ntsc-j

antibodies but they are not attached or

bound to any in design right because

remember in all these reactions we need

to deliver the output for delivering it

the best way to use an enzyme substrate

reaction to give a color right so this

antibody that represent in our RN t HCG

having enzyme bound to it but the

antibodies that are present in T region

are simply an taste such antibody do not

have any enzyme but in Tyrian we are

having many of this ntsc-j antibody

along with a die right along with small

let's say desire the die so this thing

is present in the P region right so if

you look at the our region thing this is

present in our this is present in T now

what presence in control in control

region there is another presence of

presence of another type of antibody

those are

anti-mouse antibody now remember the FC

portion of all all of this antibody that

represent in R and T are generated in

Mouse so the antibody that are present

in CR control region tend to bind with

this FC portion of this antibody that

represent in R and T right because this

antibody that are present in C region R

NP Mouse antibody so the final type of

antibody these are anti Mouse antibody

and also in the seed region we are also

having some die sometime right so this

is what we have seen in the sea region

so these are the three regions and three

different varieties of antibody mixtures

are placed now what is the principle

once we put you in there with the HCG

now suppose there is the presence of HCG

so let's say there is a positive

confirmation of pregnancy so if I look

at the positive results the presence of

HCG is there now what will happen once

we put it into the sample loading area

capillary action will draw it towards

this direction let me take the other

color capillary action will draw it to

this direction right so once this HCG is

moving along with the using it reaches

the our region right even by our region

contains the antibody and thct antibody

so the HCG molecules will bound with

this R this this a and K HCG antibody in

the our region right so they are bound

now right then what will happen after

the binding is done they will washed out

remember that's a very important stage

so actually though all the antibody that

are present in our after binding with

HCG they are washed out and they are

also carried so auntie HCG antibody is

now being carried up from this our

region towards the T region now remember

in the T region we are also having an

THC antibody so in this region what we

are going to see that they are having

this an THC antibody along with the dye

so what it will be doing here remember

so this is the antibody that we are

finding along with the dye right so dye

is present this is happening in the T

region and those antibody that is coming

from the origin remember because those

antibodies are being washed out so

though and those antibodies that are

coming it will look like this along with

this HCG right so now the antibody from

our region bonbon with HCG will come and

been attached with the antibody that are

present in the T remember because both

the antibody present in TNR are NT HCG

so they're kind of form a sandwich like

structure having the HCG in the middle

now remember the antibodies that are

coming along with the wash they are

having ensign set us to it right and

there is the presence of dye in the test

region so the enzyme along with the dye

so blue dye here along with the diag

work together and it is giving us the

dyes break down it is broken down into a

particular color actually it's a pink

color so it will give a pink coloration

so pink coloration will be observed

there okay and then once it is done

again it is moving along with this

process so once it is moving so rest of

them are done and and those antibody or

those antibody coming from our which is

not bound with this division also being

washed away so they are washed away and

they are going towards the sea region

remember sea region there is an teemo's

antibody and now there will be this our

antibody of the our region bound with

HCG right so in this region this our

antibody so the FC portion of the all

antibody will be targeted by the

anti-mouse antibody because these these

antibodies of R and T region generated

in Mouse so so the FC portion is fragile

to bound with the this anti

see so the antibody along with AF a B

portion will bind it the FC region of

the other antibody which is washed here

and then the dye will be there it will

give us a coloration so the coloration

will give again another pink coloration

so ultimately if there is a presence of

HCG in the urine

it will give to color or to bands in the

strip one for the taste one for the

control right now what happens if there

is no HCG in the sample in that case in

that case same thing begins sample is

loaded it has been carried and once it

reaches the origin so you know HCG is

there no HCG is there so no edge is

bound with this our region or antibody

present in our region right so our

region antibody are free from any HCG so

again those antibodies are being washed

out it reaches the T region remember so

now the now what situation arises we are

at this t terminal and we are also

getting antibody from R so these are the

our antibodies remember but there is no

HCG present so as there is no ACG

present there won't be formation of any

sandwich like structure that we have

seen in before so in this case there

will be no attachment of the our

antibodies with the T antibodies by ICG

so no attachment so ultimately it will

also be washed through this region so no

dye precipitation will be seen no band

will be seen in the test right because

the only way it will show the band if

there is a contact of our antibody and T

antibody via the presence of AC gene

between them right then then only the

enzyme will break down the dye and it

will give the pink color but in this

case though it is carrying load our

antibody is carrying the enzyme but

there is nothing to attach or to conduct

the signal as a result there won't be

any activity of enzyme substrate and as

a result there will be no band now then

what happens again this region of the t

antibodies are again washed out and it


which is the sea region so once they're

reaching in the sea region there is this

this antibody that are present in sea


the principle will be the same just like

the previous because with the abd region

of the sea region antibody will bound

with the FC portion of this our antibody

as a result the die will be precipitated

and we will see our color in the CDC

right so if there is an ASA gene - it

will give only one band so if the

patient is HCG plus it will give two

bands so two band will confirm the

presence of a cg in the urine so it

confirms the pregnancy one band is not

confirming the pregnancy but remember

the presence of the control band is very

very important because if there is no no

precipitation or no line in scene in the

control region that means that strip is

not working because if the strip is

working we'll always end up with a band

in the control region right because

that's how the process is developed it's

not only important to check that whether

it is HCG positive or negative but also

it is we need to make sure if we need to

check that whether the strip is working

or not if that strip works fine then

obviously you'll see a bond at least one

band in the sea region right but if

there is a ciggy positive you are going

to see two bands because one for the

sandwich structure formation another for

the anti Mouse interaction right so

that's how actually pregnancy test works

and remember the presence of this this

whole process is kind of very crude way

of determining obviously the presence of

aces in blood is the best way to go but

actually the pregnancy test kits that

are available normally kind of 95 or

above 95% to 98% sure so it is kind of

good taste because the presence of HCG

in high concentration or in urine

definitely shows the presence of

pregnancy so that's the neat pregnancy

test guys thank you