Ptc Testing Lab Report
PTC Testing Lab
11/12/13
Abstract:
The main purpose of this lab is to determine that you have the dominant PTC gene or recessive PTC gene. PTC testing is a method used to test for a genetic trait. People who have dominant gene taste PTC (phenylthiocarbamide), and people who have recessive do not taste PTC. This trait is passed genetically from parents to their children, so that if a person has the trait, then at least one of their parents had the trait as well (New York Science Teacher). Approximately 75% of individuals are tasters, and 25% are non-tasters (StewartKhataan). Gel electrophoresis is used to separate DNA fragments by length of molecules. Smaller segments move more easily than larger segments. …show more content…
So the segments are separated by length and you will be able to figure out genotype of individuals. In this lab, experiment of phenotype was a success, but experiment of genotype was not. Therefore, we only have a result of phenotypic part.
Introduction:
In 1931, a chemist named Arthur Fox was pouring powder of PTC into a bottle. Accidentally, powder of PTC blew into the air and his friends complained about the bitterness of PTC. However Arthur Fox tasted nothing at all. He was curious how they could taste PTC differently. Fox let his friends and family taste PTC. He found out some people tasted intense bitterness, and still others tasted only slight bitterness. Some people tasted nothing. Fox studied about PTC and he figured out PTC (phenylthiocarbamide) is an organic compound that either tastes very bitter or tasteless all depending on the genes of the taster (Merritt). The ability to taste PTC is a dominant genetic trait controlled by the gene TAS2R38, located on chromosome7 (WoodingStephen). PTC testing is a method used to test for a genetic trait. People who have dominant genetic trait taste PTC and people who have the recessive genetic trait do not taste PTC (New York Science Teacher). The Purpose of this lab is the learning of the genetic polymorphisms in the ability to taste PTC. We will use PCR to amplify a fragment of the Tas2R38 gene from the DNA extracted from the cheek cells. My null hypothesis is that we will not have people who taste PTC and my alternative hypothesis is that we will have people who taste PTC as bitter.
Materials and Method:
This experiment included collection and extraction of DNA, isolation, PCR, restriction enzyme digestion, and gel electrophoresis.
We began this lab by isolating DNA. We obtained 14 ml of sterile saline solution and poured this solution into my mouth for extracting DNA from my cheek cells. We transferred the solution into a centrifuge tube and centrifuge my tube at top speed for 10 minutes to obtain a cheek cell pellet. After pelleting, we poured out liquid from the tube as much as possible. However we had to make sure that we did not interrupt pellet while pouring out liquid. We placed this tube on ice and added 500 μl of 10% Chelex to the pellet. We used a micropipette for doing this. We transferred 500 μl of the sample to a 1.5 ml microcentrifuge tube and it boiled for 10 minutes and placed the tube on ice for 1 minute to isolate the DNA. After the DNA was extracted and isolated, we used PCR to amplify the fragment of the Tas2R38 located on chromosome 7. We added 5 µl of my DNA to the PCR tube by using micropipettes. We used restriction enzymes to cut my PCR product. We added 20 µl of my PCR product to the restriction enzyme digestion tube containing 1 µl Fnu4HI restriction enzyme and 2.5 µl 10X NEBuffer and placed in a 370C waterbath for 1 hour. The amplified region was digested and we used electrophoresis gel to determine that we had the bitter taster gene which is Tas2R38. We assembled the electrophoresis casting tray and weighed out 0.5 g of agarose into a flask. I …show more content…
added 50 ml of TBE buffer to the flask and swirled it to mix. We placed the agarose in microwave for 1 minute, but we stopped every 10-15 seconds to swirl it. The solution became clear. So we poured this solution into the casting tray and allowed it to polymerize. After it polymerized, we slid the gel off the casting tray onto the platform in the electrophoresis chamber. We poured TBE buffer to cover the gel. After the DNA is digested, we placed 10 µl of the digest into a new 1.5 ml microcentrifuge tube and added 2 µl of TrackIT dye. We loaded the DNA into a well of the gel and let samplers are loaded. We placed the lid on the chamber matching the negative and positive pole colors. We plugged the power supply and observed the tracking dye. In a gel electrophoresis, each band represents a different length of DNA. DNA toward the positive charge because DNA has a negative charge due to phosphate. Shorter segments move more easily and fast in the gel and longer segments move slowly, so the strands in the gel are separated by length. Observing location of segments allowed us to determine that individual has which allele combinations (TT, Tt, and tt).
Results:
In our lab, we had a 7 types of ethnic group: White, Black, Asian, Hispanic, Filipino, Native Americans, and Indian. According to our lab data, 32 Asians were tasters and 5 were non-tasters. For percentile scale, 86.49% of Asians were tasters and 13.51% were non-tasters. For Blacks, 26 people were tasters and 2 people were non-tasters. For percentile scale, 92.86% of Blacks were tasters and 7.14% were non-tasters. For Filipinos, 2 people were tasters and there were no non-tasters. For percentile scale, 100% of Filipinos were tasters. For Hispanic, 9 people were tasters and 3 people were non-tasters. For percentile scale, 75% of Hispanic were tasters, and 25% were non-tasters. For Indian, only one person was taster. For percentile scale, 100% of Indians were taster. For Native Americans, 1 person was taster and another person was non-taster. For percentile scale, 50% of Native Americans were taster and non-taster. For White, 15 people were tasters and 7 people were non-tasters. For percentile scale, 68.18% of Whites were tasters, and 31.82% were non-tasters. I could taste bitterness of the PTC paper and my phenotype was taster. We do not have a data from genotype because of experiment failure.
Discussion:
As I mentioned earlier, I expected 75% of population are tasters and 25% are non-tasters.
However, according to our data, 83% of individuals were taster and 17% were non-tasters. I think reason of this error is we did phenotype experiment with just small amount of individuals. According to standard data for phenotype of individuals related to ethnicity, 10~24% of Asians were non-tasters (StewartKhataan). In our data, 13.51% of Asians were non-tasters and this result was very close to standard data. For Blacks, standard data expected there are 2.14~4.89% non-tasters (StewartKhataan). In our data, 7.14% of Blacks were non-tasters. Our result was slightly off than standard data, and I think this error came from small population for sample. For Whites, standard data expected there are 31% non-tasters (StewartKhataan). In our data, 31.82% of Whites were non-tasters. This result was quite close to the standard data. For Indians, standard data expected there are 41% non-tasters (StewartKhataan). However, in our data 0% of Indians were non-taster. I think reason of this huge error came from extreme small amount of population for sample. We only had 1 Indians for this experiment. According to standard data for phenotype of individuals related to gender, the percentage of tasters of men and women are about the same (StewartKhataan). In our data, 84.2% of females were tasters and 79.2% of males were tasters. This result matched with standard
data.
My phenotype was tasters. Most of our data matched with expected standard data. However, some data did not match with standard data due to small population for sample. In the future lab, if we have a larger population for sample, we would have more accurate results. I rejected all of my null hypothesis and agreed with my alternative hypothesis. Because we had people who taste PTC as bitter.
Tables and Graphs:
Ethnicity
Taster
Non-taster
Asian
32
5
Black
26
2
Filipino
2
0
Hispanic
9
3
Indian
1
0
Native American
1
1
White
15
7
Table1. Number of Taster and Non-taster based on ethnicity.
Graph1. This graph shows number of individuals of taster and non-taster in each ethnic group.
Ethnicity
% of tasters
% of non-tasters
Asian
86.49%
13.51%
Black
92.86%
7.14%
Filipino
100%
0%
Hispanic
75%
25%
Indian
100%
0%
Native American
50%
50%
White
68.18%
31.82%
Table2. Percentile of Taster and Non-taster based on ethnicity.
Graph2. This graph shows percentile of individuals of taster and non-taster in each ethnic group.
Table3. Number of Taster and Non-taster based on gender.
Gender
Taster
Non-taster
Male
38
10
Female
48
9
Graph3. This graph shows number of individuals of taster and non-taster in each gender.
Gender
Taster
Non-taster
Male
79.2%
20.8%
Female
84.2%
15.8%
Table4. Percentile of Taster and Non-taster based on gender.
Graph4. This graph shows percentile of individuals of taster and non-taster in each gender.
Works Cited Page
Merritt. n.d. 22 10 2013 .
"New York Science Teacher." 4 2011. 22 10 2013 .
Sheehan, Christopher. n.d. 22 10 2013 .
Stewart, Khataan. "Journal of nutrigenetics and nutirgenomics." 2009. 251-256.
Tepper, Beverly. "Genetic Variation in Taste Sensitivity." INTERNATIONAL SYMPOSIUM ON OLFACTION AND TASTE, 2009. 126-139.
Wooding, Stephen. n.d. 22 10 2013 .
11/12/13
Abstract:
The main purpose of this lab is to determine that you have the dominant PTC gene or recessive PTC gene. PTC testing is a method used to test for a genetic trait. People who have dominant gene taste PTC (phenylthiocarbamide), and people who have recessive do not taste PTC. This trait is passed genetically from parents to their children, so that if a person has the trait, then at least one of their parents had the trait as well (New York Science Teacher). Approximately 75% of individuals are tasters, and 25% are non-tasters (StewartKhataan). Gel electrophoresis is used to separate DNA fragments by length of molecules. Smaller segments move more easily than larger segments. …show more content…
So the segments are separated by length and you will be able to figure out genotype of individuals. In this lab, experiment of phenotype was a success, but experiment of genotype was not. Therefore, we only have a result of phenotypic part.
Introduction:
In 1931, a chemist named Arthur Fox was pouring powder of PTC into a bottle. Accidentally, powder of PTC blew into the air and his friends complained about the bitterness of PTC. However Arthur Fox tasted nothing at all. He was curious how they could taste PTC differently. Fox let his friends and family taste PTC. He found out some people tasted intense bitterness, and still others tasted only slight bitterness. Some people tasted nothing. Fox studied about PTC and he figured out PTC (phenylthiocarbamide) is an organic compound that either tastes very bitter or tasteless all depending on the genes of the taster (Merritt). The ability to taste PTC is a dominant genetic trait controlled by the gene TAS2R38, located on chromosome7 (WoodingStephen). PTC testing is a method used to test for a genetic trait. People who have dominant genetic trait taste PTC and people who have the recessive genetic trait do not taste PTC (New York Science Teacher). The Purpose of this lab is the learning of the genetic polymorphisms in the ability to taste PTC. We will use PCR to amplify a fragment of the Tas2R38 gene from the DNA extracted from the cheek cells. My null hypothesis is that we will not have people who taste PTC and my alternative hypothesis is that we will have people who taste PTC as bitter.
Materials and Method:
This experiment included collection and extraction of DNA, isolation, PCR, restriction enzyme digestion, and gel electrophoresis.
We began this lab by isolating DNA. We obtained 14 ml of sterile saline solution and poured this solution into my mouth for extracting DNA from my cheek cells. We transferred the solution into a centrifuge tube and centrifuge my tube at top speed for 10 minutes to obtain a cheek cell pellet. After pelleting, we poured out liquid from the tube as much as possible. However we had to make sure that we did not interrupt pellet while pouring out liquid. We placed this tube on ice and added 500 μl of 10% Chelex to the pellet. We used a micropipette for doing this. We transferred 500 μl of the sample to a 1.5 ml microcentrifuge tube and it boiled for 10 minutes and placed the tube on ice for 1 minute to isolate the DNA. After the DNA was extracted and isolated, we used PCR to amplify the fragment of the Tas2R38 located on chromosome 7. We added 5 µl of my DNA to the PCR tube by using micropipettes. We used restriction enzymes to cut my PCR product. We added 20 µl of my PCR product to the restriction enzyme digestion tube containing 1 µl Fnu4HI restriction enzyme and 2.5 µl 10X NEBuffer and placed in a 370C waterbath for 1 hour. The amplified region was digested and we used electrophoresis gel to determine that we had the bitter taster gene which is Tas2R38. We assembled the electrophoresis casting tray and weighed out 0.5 g of agarose into a flask. I …show more content…
added 50 ml of TBE buffer to the flask and swirled it to mix. We placed the agarose in microwave for 1 minute, but we stopped every 10-15 seconds to swirl it. The solution became clear. So we poured this solution into the casting tray and allowed it to polymerize. After it polymerized, we slid the gel off the casting tray onto the platform in the electrophoresis chamber. We poured TBE buffer to cover the gel. After the DNA is digested, we placed 10 µl of the digest into a new 1.5 ml microcentrifuge tube and added 2 µl of TrackIT dye. We loaded the DNA into a well of the gel and let samplers are loaded. We placed the lid on the chamber matching the negative and positive pole colors. We plugged the power supply and observed the tracking dye. In a gel electrophoresis, each band represents a different length of DNA. DNA toward the positive charge because DNA has a negative charge due to phosphate. Shorter segments move more easily and fast in the gel and longer segments move slowly, so the strands in the gel are separated by length. Observing location of segments allowed us to determine that individual has which allele combinations (TT, Tt, and tt).
Results:
In our lab, we had a 7 types of ethnic group: White, Black, Asian, Hispanic, Filipino, Native Americans, and Indian. According to our lab data, 32 Asians were tasters and 5 were non-tasters. For percentile scale, 86.49% of Asians were tasters and 13.51% were non-tasters. For Blacks, 26 people were tasters and 2 people were non-tasters. For percentile scale, 92.86% of Blacks were tasters and 7.14% were non-tasters. For Filipinos, 2 people were tasters and there were no non-tasters. For percentile scale, 100% of Filipinos were tasters. For Hispanic, 9 people were tasters and 3 people were non-tasters. For percentile scale, 75% of Hispanic were tasters, and 25% were non-tasters. For Indian, only one person was taster. For percentile scale, 100% of Indians were taster. For Native Americans, 1 person was taster and another person was non-taster. For percentile scale, 50% of Native Americans were taster and non-taster. For White, 15 people were tasters and 7 people were non-tasters. For percentile scale, 68.18% of Whites were tasters, and 31.82% were non-tasters. I could taste bitterness of the PTC paper and my phenotype was taster. We do not have a data from genotype because of experiment failure.
Discussion:
As I mentioned earlier, I expected 75% of population are tasters and 25% are non-tasters.
However, according to our data, 83% of individuals were taster and 17% were non-tasters. I think reason of this error is we did phenotype experiment with just small amount of individuals. According to standard data for phenotype of individuals related to ethnicity, 10~24% of Asians were non-tasters (StewartKhataan). In our data, 13.51% of Asians were non-tasters and this result was very close to standard data. For Blacks, standard data expected there are 2.14~4.89% non-tasters (StewartKhataan). In our data, 7.14% of Blacks were non-tasters. Our result was slightly off than standard data, and I think this error came from small population for sample. For Whites, standard data expected there are 31% non-tasters (StewartKhataan). In our data, 31.82% of Whites were non-tasters. This result was quite close to the standard data. For Indians, standard data expected there are 41% non-tasters (StewartKhataan). However, in our data 0% of Indians were non-taster. I think reason of this huge error came from extreme small amount of population for sample. We only had 1 Indians for this experiment. According to standard data for phenotype of individuals related to gender, the percentage of tasters of men and women are about the same (StewartKhataan). In our data, 84.2% of females were tasters and 79.2% of males were tasters. This result matched with standard
data.
My phenotype was tasters. Most of our data matched with expected standard data. However, some data did not match with standard data due to small population for sample. In the future lab, if we have a larger population for sample, we would have more accurate results. I rejected all of my null hypothesis and agreed with my alternative hypothesis. Because we had people who taste PTC as bitter.
Tables and Graphs:
Ethnicity
Taster
Non-taster
Asian
32
5
Black
26
2
Filipino
2
0
Hispanic
9
3
Indian
1
0
Native American
1
1
White
15
7
Table1. Number of Taster and Non-taster based on ethnicity.
Graph1. This graph shows number of individuals of taster and non-taster in each ethnic group.
Ethnicity
% of tasters
% of non-tasters
Asian
86.49%
13.51%
Black
92.86%
7.14%
Filipino
100%
0%
Hispanic
75%
25%
Indian
100%
0%
Native American
50%
50%
White
68.18%
31.82%
Table2. Percentile of Taster and Non-taster based on ethnicity.
Graph2. This graph shows percentile of individuals of taster and non-taster in each ethnic group.
Table3. Number of Taster and Non-taster based on gender.
Gender
Taster
Non-taster
Male
38
10
Female
48
9
Graph3. This graph shows number of individuals of taster and non-taster in each gender.
Gender
Taster
Non-taster
Male
79.2%
20.8%
Female
84.2%
15.8%
Table4. Percentile of Taster and Non-taster based on gender.
Graph4. This graph shows percentile of individuals of taster and non-taster in each gender.
Works Cited Page
Merritt. n.d. 22 10 2013 .
"New York Science Teacher." 4 2011. 22 10 2013 .
Sheehan, Christopher. n.d. 22 10 2013 .
Stewart, Khataan. "Journal of nutrigenetics and nutirgenomics." 2009. 251-256.
Tepper, Beverly. "Genetic Variation in Taste Sensitivity." INTERNATIONAL SYMPOSIUM ON OLFACTION AND TASTE, 2009. 126-139.
Wooding, Stephen. n.d. 22 10 2013 .