Project Description/Content
Lab Write Up
Purpose: The purpose of this lab was to find out whether humans are still evolving, to gain common lab experience, and most important of all, to track our DNA history using PCR and gel electrophoresis.
Hypothesis: I hypothesize that we will use PCR to analyze my and DNA and this will lead me be able to measure the amount of alu repeats are in my DNA and I will correctly identify where my DNA originated; this will lead me to discover I’m from India.
Procedure: We worked in accordance with BABEC 2017 Bay Area Biotechnology Education Consortium.
Data: Over the course of four days I took notes on what stood out to me.
My Observations:
Day 1
Day 2
Day 3
Day 4
When we used the salt water to cleanse our mouths I noticed how foamy the solution was
I also noticed how crucial the practice of cleansing your mouth with the saltwater was because if you did not do it properly the experiment would go wrong.
On the second day, we worked with PCR. We had to be really careful with the pipettes because it’s really easy to get the wrong amount.
I also observed how small the cell pellet was.
I noticed that it was tricky to insert the DNA into the gel. You had to put the pipette tip .5 in into the gel. My hands were really shaky.
I also noticed the gel was purple because of the dye.
On the final day we analyzed our results but most people did not get results.
Below you can see a picture of the final data. Each row section is a person's work. If there is a red line present it indicates there were results.
Here is a image of my groups gel. Lane A section 8 contains my gel.
In this lab we used a 2 percent agarose gel ran at 150 v for 20 minutes and stained using gelred for 12 hours. Lane A1 and B1 have a 100 bp ladder lane 1-B-H and B-18 have a 20 ml loading dye solution. Lane A section 8 has my DNA sample I loaded. As you can see my data was inconclusive.
Analysis/Discussion:
In the picture above you can see calculations. These calculate our
genotype frequencies. A genotype frequency is the percentage of individuals within a population having a particular genotype. Genotype refers to the specific alleles that an organism carries. In this situation we used a hypothetical classroom scenario where 15 kids had +/+, 10 kids had +/-, and 12 kids had -/- (if we had gotten results we could have found what genotype we were) The objective was to find out how many of each allele each student has. If you try to find the frequency of positive alleles (37) you multiply the amount of alleles by 2 (every person has 2 alleles)
2 x 37= 74 alleles
Then you multiply by the number of actual positive alleles
2 x 25=50 positive alleles
If you divide the positive alleles by the total amount of alleles (50/74=67%)
We can also do the same for negative
44/74=.595 or 59.5% ( Frequencies don’t add up to 1.0 because it is theoretical)
Our objective for this exercise was to define allele, genotype, and phenotype, calculate allele frequencies, calculate genotype frequencies, and define and calculate Hardy-Weinberg equilibrium. The Hardy Weinberg equilibrium is model, theorem, or law, states that allele and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences.
As I stated above my results were inconclusive so there is really no definite way to prove how many alu repeats are in my DNA (in this lab). In order to perform this lab correctly, I need to eliminate all human errors.
Clearly there were errors with this experiment because it did not work. Some of the reasons could have been:
The correct amount of solution wasn't pipetted.
The container wasn't in the ice long enough.
You did not centrifuge for the right amount of time.
You did not thoroughly clean your mouth with salt water.
You did not label your DNA sample clearly enough and it got erased.
Those are just a few reasons why this lab could have gone wrong
A few ways we could improve this lab could be to…
Try to completely minimize human error. If we spent more than a week, trying to get every detail correct, checking in as soon as each step was completed, that could have been a way to successfully complete the lab
The room was also very small. If we performed the lab in a larger area where it wasn't less cramped, I think the lab would have better results.
If we also inserted more DNA I think the lab would have a better chance of succeeding. If we did use more DNA less of it would get washed out.
Time management was also an issue. Waiting and listening for instruction took a big chunk of our time in the lab.
This data means the reasons listed above could have played into students not getting results. This could lead into further investigations because if we redo this lab and eliminate all the errors, the majority of us would probably get results.
Hypothesis:
My hypothesis turned out to be false. I did not correctly identify how many alu repeats I had in my DNA due to the many errors that could have had an influence. There is really no way I can find out where my DNA came from unless I do the lab over again and execute it perfectly.
Conclusion:
Throughout this project I discovered that this lab is difficult to execute. Most of the kids in the class did not get results. In this experiment we tried use PCR to analyze DNA which will lead us be able to measure the amount of alu repeats are in my DNA. This will allow us to correctly identify where our DNA originated. As you can see in the picture it shows the DNA samples and the data can be seen if there is a purple line in the same lane. My DNA takes the space of lane A slot 8. Don't see anything? Like most people I did not get data. That means somewhere throughout the lab I made an error. Whether it was something like not fully submerging it in ice, or leaving it in the heat for too long. Some evidence that can back this up is when we had to pour out all the liquid solution and keep that small white object in the container. During that I had to restart because I had accidently poured out the object. So I went back and centrifuged it again. This was probably vital to the lab because the whole lab was based around the DNA aspect. Another piece of evidence could have been when we had to insert our solution into the purple gel. This part was also crucial because we had to put the pipette exactly 0.5 inches into the gel and my hand was really shaky. This was all valuable evidence that could have played into me not getting results. I have come to the conclusion that one of these mistakes caused me to not get results.
Purpose: The purpose of this lab was to find out whether humans are still evolving, to gain common lab experience, and most important of all, to track our DNA history using PCR and gel electrophoresis.
Hypothesis: I hypothesize that we will use PCR to analyze my and DNA and this will lead me be able to measure the amount of alu repeats are in my DNA and I will correctly identify where my DNA originated; this will lead me to discover I’m from India.
Procedure: We worked in accordance with BABEC 2017 Bay Area Biotechnology Education Consortium.
Data: Over the course of four days I took notes on what stood out to me.
My Observations:
Day 1
Day 2
Day 3
Day 4
When we used the salt water to cleanse our mouths I noticed how foamy the solution was
I also noticed how crucial the practice of cleansing your mouth with the saltwater was because if you did not do it properly the experiment would go wrong.
On the second day, we worked with PCR. We had to be really careful with the pipettes because it’s really easy to get the wrong amount.
I also observed how small the cell pellet was.
I noticed that it was tricky to insert the DNA into the gel. You had to put the pipette tip .5 in into the gel. My hands were really shaky.
I also noticed the gel was purple because of the dye.
On the final day we analyzed our results but most people did not get results.
Below you can see a picture of the final data. Each row section is a person's work. If there is a red line present it indicates there were results.
Here is a image of my groups gel. Lane A section 8 contains my gel.
In this lab we used a 2 percent agarose gel ran at 150 v for 20 minutes and stained using gelred for 12 hours. Lane A1 and B1 have a 100 bp ladder lane 1-B-H and B-18 have a 20 ml loading dye solution. Lane A section 8 has my DNA sample I loaded. As you can see my data was inconclusive.
Analysis/Discussion:
In the picture above you can see calculations. These calculate our
genotype frequencies. A genotype frequency is the percentage of individuals within a population having a particular genotype. Genotype refers to the specific alleles that an organism carries. In this situation we used a hypothetical classroom scenario where 15 kids had +/+, 10 kids had +/-, and 12 kids had -/- (if we had gotten results we could have found what genotype we were) The objective was to find out how many of each allele each student has. If you try to find the frequency of positive alleles (37) you multiply the amount of alleles by 2 (every person has 2 alleles)
2 x 37= 74 alleles
Then you multiply by the number of actual positive alleles
2 x 25=50 positive alleles
If you divide the positive alleles by the total amount of alleles (50/74=67%)
We can also do the same for negative
44/74=.595 or 59.5% ( Frequencies don’t add up to 1.0 because it is theoretical)
Our objective for this exercise was to define allele, genotype, and phenotype, calculate allele frequencies, calculate genotype frequencies, and define and calculate Hardy-Weinberg equilibrium. The Hardy Weinberg equilibrium is model, theorem, or law, states that allele and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences.
As I stated above my results were inconclusive so there is really no definite way to prove how many alu repeats are in my DNA (in this lab). In order to perform this lab correctly, I need to eliminate all human errors.
Clearly there were errors with this experiment because it did not work. Some of the reasons could have been:
The correct amount of solution wasn't pipetted.
The container wasn't in the ice long enough.
You did not centrifuge for the right amount of time.
You did not thoroughly clean your mouth with salt water.
You did not label your DNA sample clearly enough and it got erased.
Those are just a few reasons why this lab could have gone wrong
A few ways we could improve this lab could be to…
Try to completely minimize human error. If we spent more than a week, trying to get every detail correct, checking in as soon as each step was completed, that could have been a way to successfully complete the lab
The room was also very small. If we performed the lab in a larger area where it wasn't less cramped, I think the lab would have better results.
If we also inserted more DNA I think the lab would have a better chance of succeeding. If we did use more DNA less of it would get washed out.
Time management was also an issue. Waiting and listening for instruction took a big chunk of our time in the lab.
This data means the reasons listed above could have played into students not getting results. This could lead into further investigations because if we redo this lab and eliminate all the errors, the majority of us would probably get results.
Hypothesis:
My hypothesis turned out to be false. I did not correctly identify how many alu repeats I had in my DNA due to the many errors that could have had an influence. There is really no way I can find out where my DNA came from unless I do the lab over again and execute it perfectly.
Conclusion:
Throughout this project I discovered that this lab is difficult to execute. Most of the kids in the class did not get results. In this experiment we tried use PCR to analyze DNA which will lead us be able to measure the amount of alu repeats are in my DNA. This will allow us to correctly identify where our DNA originated. As you can see in the picture it shows the DNA samples and the data can be seen if there is a purple line in the same lane. My DNA takes the space of lane A slot 8. Don't see anything? Like most people I did not get data. That means somewhere throughout the lab I made an error. Whether it was something like not fully submerging it in ice, or leaving it in the heat for too long. Some evidence that can back this up is when we had to pour out all the liquid solution and keep that small white object in the container. During that I had to restart because I had accidently poured out the object. So I went back and centrifuged it again. This was probably vital to the lab because the whole lab was based around the DNA aspect. Another piece of evidence could have been when we had to insert our solution into the purple gel. This part was also crucial because we had to put the pipette exactly 0.5 inches into the gel and my hand was really shaky. This was all valuable evidence that could have played into me not getting results. I have come to the conclusion that one of these mistakes caused me to not get results.
Key Terminology
Allele: a given gene. In a diploid organism, one that has two copies of each chromosome, two alleles make up the individual's genotype. In this project we looked at each alleles to see how many alu repeats were in our DNA.
Homozygous: When an individual has two of the same allele. Homozygousis a word that refers to a particular gene that has identical alleles on both homologous chromosomes. It is referred to by two capital letters (XX) for a dominant trait, and two lowercase letters (xx) for a recessive trait.
Heterozygous: When an individual has two different alleles. If the organism has one copy of two different alleles, for example Aa, it is heterozygous.
Gel Electrophoresis: a laboratory method used to separate mixtures of DNA, RNA, or proteins according to molecular size. Gel electrophoresis is used to separate macromolecules like DNA, RNA and proteins. DNA fragments are separated according to their size. Proteins can be separated according to their size and their charge.
Sterile Technique: Strategies used to reduce contamination like wearing gloves, reducing exposure to air, etc. We practiced sterile technique by limiting exposure of outside things when we were pippeting.
Homozygous: When an individual has two of the same allele. Homozygousis a word that refers to a particular gene that has identical alleles on both homologous chromosomes. It is referred to by two capital letters (XX) for a dominant trait, and two lowercase letters (xx) for a recessive trait.
Heterozygous: When an individual has two different alleles. If the organism has one copy of two different alleles, for example Aa, it is heterozygous.
Gel Electrophoresis: a laboratory method used to separate mixtures of DNA, RNA, or proteins according to molecular size. Gel electrophoresis is used to separate macromolecules like DNA, RNA and proteins. DNA fragments are separated according to their size. Proteins can be separated according to their size and their charge.
Sterile Technique: Strategies used to reduce contamination like wearing gloves, reducing exposure to air, etc. We practiced sterile technique by limiting exposure of outside things when we were pippeting.
Reflection
Out of the three projects this product was by far the hardest. This project was especially hard because every single detail and a little aspect of the project must be correct in order for it to work. Most of the kids who did the slab did not get results. This lab was very tricky and could’ve went wrong in the number of places. For example when we use the micropipettes it is really easy to mess up by getting the wrong amount of solution. Another area where this lab could’ve went wrong was when we give our DNA sample. The step is crucial because if you do not provide enough DNA the whole I will spiral downhill. Although we worked in groups this lab was mostly individual because we were the ones using our own DNA. A few things I’ve learned in this lab is how to micropipette, centrifuge a solution, and insert a solution into a gel. If I was to do this lab again I would be really careful to execute it perfectly. When we did this project in the lab it was kind of rushed, so if I was to do this again I would make sure I would do every step perfectly. Next time I will work on my attention to detail so bad things like this won’t happen.