 students now this is the last stage of the chromosome on preparation steps this is one of the very final step that is known as the slide preparation we will now prepare the slides for visualizing the chromosomes so you can see we have the slides here keep in mind the slide should be in this tilted fashion they have to be placed in tilted fashion so that when we put the cells on the slides they can easily move along with the length of the slides now again I take this tip this is the suponator keep in mind that this way is the one of that suponator which was quite clear and the it has palette in it now I mix it well so that the palette get mixed in it and I will take around let's say five hundred micro of it and just I will add two to three drops on each side one I have dropped it let it to move down the line now we have added the cells on the slides after dropping the cell now let it to be moved down to the bottom of the slide and then let it to be tried for further drawing we will put these both slides into an oven at 60 degree centigrade they will remain overnight they are in the oven for 60 degree centigrade and then next day we will use the same slides for the process of bending okay guys now as you can see we have very well dried slides they have been aged very well now we will bend these slides the bending is a very important part of the chromosome preparation because without bending we cannot identify individual chromosomes or the problems or abrasions which are present in the chromosome that's why bending is really one of the most important step in the process of chromosome preparation there are different types of bending but before coming to those different types of bending let me give you a little bit about or tell you a little bit about the principle of bending in chromosomal bending we make use of the differential composition of the chromosome differential composition in the sense that you know the chromosomes are made up of DNA and proteins the proteins make the DNA in the chromosome in a compactified form in other words chromosome are in their shape as we look at them is because of the protein the second differential composition of chromosome is because of the different frequency of AT and C and G nucleotides in different portions of the chromosome in certain portion of the chromosomes and T are numerous in the other C and G nucleotides are numerous as a result of which we see differential composition of chromosome along their whole length so some part of the chromosome consequently is known as the heterochromotone and the some part is known as zucromotone in the bending we make use of those differences so that in certain parts of the chromosome we have darker bands in the other parts we have lighter bands because each chromosome have differential composition as a result each chromosome will give different bands and on the basis of those differences in the bands we can say that this is chromosome 1 this is chromosome 2 this is chromosome 3 and so on and so forth now let's move to its bending process in the chromosome bending we have different solution one is the I mean before I straight away come to the bending let me tell you a little bit about different types of banding there is G banding there is C banding there is T banding there are banding there is Q banding all these are different types of chromosome banding but for the sake of clarity and for the sake of better understanding of the whole process of banding we will focus here for on G banding but keep in mind that whatever banding is it it again depends it is because of the reason that the chromosomes are of different composition so the banding's patterns we see as a result of all these types of banding are because of this different composition of the chromosomes so we are going to show you the G banding now because this is one of the most commonly used technique it is used in each and every lab in the world in Pakistan or whatsoever so let's now show you how we do the G banding G here is for Jimza is because of the stain the Jimza stain which we use for the G banding now in the G banding this is the first solution this one this is the trypsin it contains trypsin it in you know trypsin is an enzyme which digest the proteins this is the phosphate buffer and this is the Jimza strain so first we will trypsinize this slide for around let's say 10 to 20 seconds you give a trial and error you can do it for 40 seconds you can do it for 60 seconds but we generally do it for 20 seconds but for us sometimes we also do it for 10 seconds but that's again after the trial and error so I have a watch I am doing it for 20 seconds for 15 seconds now I dip it in the buffer now after the treatment with the buffer now I am dipping it into the Jimza so for three minutes I will dip it into the Jimza okay now we have this slide very well stained now with the Jimza uh let's we take it out and then clean it a little bit with the distro water here gently now it is well clean it's well clean now so let us put it over here to get dried fine now it's here it could be dried in 10 to 15 minutes or you can air dry it with any instrument if you have and we will after it gets dried we will see it in the microscope okay guys now let us see the final results of our three to four day of hard work now we will see the chromosomes in the microscope and I am sure we will have a very very nice photograph why I'm sure because we really work very hard for it okay so this is the microscope you know let's turn on the light let's first do it on just in for the chromosomes at at the magnification of 10 at 10x we use the 10x uh objective lens actually you know magnification is nothing but the product of magnification of the objective lens and the ip so yes now I can see the lots of lots of lots of metaphases here now let's see these metaphases at higher resolution that is what 40x wow now this is beautiful this is really really lovely yes now I will soon share with you the photograph of what I have seen and let me tell you guys there is not anything in the whole world or maybe in the whole universe as far as we know more beautiful than these people the chromosomes our unit the unit of our inheritance with us and thank you very much for watching and listening