How are their DNAs matched to each other?

Hey guys!




So now we're going to look at Question 6:

The DNA profile showed evidence for a father and son. In addition there was DNA profiling pattern that matched one living twin (Tanya Rosilawati). With this, match the evidence to these victims who were earlier filed for missing persons. Explain your rationale.

So that's question 6. Easy one we got this time, eh? No? It's okay. I'll walk you through it bit by bit! :)



The first you have to know is, what is the polymerase chain reaction (PCR) first in order to know what DNA Profiling is. If you still can't recall how it works, I'll just briefly explain the whole process to you again as a quick revision. But if you still can remember it, then feel free to skip this revision part and quickly get yourself back on the track! :)


Here's a video I made a while back that explains the whole PCR process. I'll see you back in a few minutes. Enjoy!

Okay. Does that refresh back your memory? Do you understand it better now? Yeah? Good.

Now moving on to DNA Profiling.



So what is a DNA profile? 

DNA profiles are encrypted sets of numbers that reflect a person's DNA makeup, which can also be used as the person's identifier. As you have all heard this at some point in your life, no one's fingerprint is the same as another. Same theory applies to your DNA.And unless you have a monozygotic/identical twin, NO ONE will have the same DNA as you!

THIS my dear readers is basically the point for forensic scientist to cast their magic on and find whether the DNA samples harvested from the bone and skull remains are actually from the victims that we have stated before.

Okay, now that we have some DNA samples, they are then undergo PCR in order for us to see the different types of bands shown by the DNA fragments in the DNA profiles.


Let's take a look at the DNA profile of the DNA samples that was taken from a young male adult skull..

Eventhough we know that this DNA profile belongs to Adi Hortono, we still need a solid evidence to prove that it is 110% his.

So how are we going to do that?

First of all, since Adi Hortono is already in the database, we can track his mother (Sussilawati Hortono) and ask her for a consent to go through his belongings (such as clothings etc.). From there, say we obtained a few hair strands that were stuck on one of his jumpers. The hair strands contain DNAs. The DNAs are then undergo the same process in order to view in a DNA profile form.

Let's compare those that Adi's and the one that we found from the crime scene shall we?

 

Aha! It's a matched! See how the width and patterns of the bands are exactly the same? Remember, all DNA profiles are unique to every individual except IDENTICAL twins!









Now, let's take a look at the DNA profile of the DNA samples that we obtained from an adult male skull at the crime scene.
Same as Adi's case, evethough we know that this is Herman's DNA, we still need a solid proof for the court. It's the law.

So far we've been very lucky. Sussilawati has still kept her husband's favourite shaver and she allows us to take it in to strip some DNA samples from it. And boy we're bloody lucky! Facial hairs! Eureka! Now let us turn the DNA samples into a DNA profile form quickly! Oh I'm so excited!!





So here's the result.. IT'S A MATCHED!!! :D

 




Now that bothe of the skull found is confirmed to be that of Adi and Herman's Hortono, How sure are we still that they both are related to each other? Let alone having a blood-relations, father and son???

A child will inherit both of the 'unique' patterns of each parents. Meaning, the child will have a DNA profile pattern that is match-up of both parents and ONLY from both parents.

So we already took a mouth swab from Mrs Sussilawati in order to take some of her DNA samples. And we already runned them in PCR and got the DNA profile. Now let's compare the three of the DNA samples side by side..

See how Adi has both of his parent's pattern? A mash-up to be exact. And notice that all of Adi's band patterns can exactly be found on either BOTH of his parents? 

This 110% proves that Adi Hortono is the son of Herman Hortono and Sussilawati Hortono!!

Okay.... Enough with the awesomeness haha.

Next stop, identifying whether the DNA sample harvested belongs to Anya Suriati, whom was filed in the missing persons' list.

As you all should have known by now, Anya has an identical twin sister, Tanya Rosilawati. Believe it or not, this actually makes the whole DNA profiling process much easier.

First of all,let's try to understand the basic differences between fraternal and identical twins.



Picture adapted from: www.genomesunzipped.org/wp-content/uploads/2010/12/Identical-fraternal-sperm-egg.png

Based on the picture,you can see that identical twins are actually formed from one egg fertilized by one sperm which later divide and form two separate embryos.Hence, both of the twins will share the same genetic profile.
On the other hand, fraternal twins are developed from two separate eggs being fertilized by two different sperms and later forms two separate embryos.Since everything happens separately, each of the twin will actually have his/her own set of genetic profile, which is different than of the counterpart.

So after the explanation above, do you get why I said having a twin actually makes the whole DNA profiling and identification process easier?
Bingo! Yup, if the DNA sample that we have actually matches the DNA sample we collect from Tanya Rosilawati (by the means of hair, blood etc.), then the victim will definitely be Anya Suriati! Check out their DNA matching below:





  

Well, I guess it's been a long post for you guys but anyhow, got your doubts regarding DNA profiling cleared? If so, then do give yourself a big clap as not everybody can be a dental investigator but you, my friend are now a big step closer to be one! Haha:D
Hope you have enjoyed everything and stay tuned as WE WILL BE BACK