PLTW 1.2.2
Activity 1.1.3 Using DNA to Identify Pathogens
Describe the limitations of traditional methods of identifying bacteria.
Traditional methods include judging by phenotypic characteristics. This could be a problem if two bacteria looked similar because they could easily be confused.
Summarize the goal of each of the six parts of the lab.
Sample Prep
First we need to extract the DNA from the bacterial wall
PCR Amplification
Create millions of copies of the initial DNA
PCR Purification
Filter out DNA from primers and enzymes
Sequencing Prep
Run more PCR to make copies of DNA at various lengths
DNA Sequencing
Sequence machine runs gel electrophoresis to identify nucleotides and determine sequence.
Sequence Analysis
Computer determines full DNA sequence which can be run and compared.
Explain how fluorescent markers help determine a nucleotide sequence.
Each nucleotide is assigned a certain color.
Conclusion
1 How can scientists identify specific bacteria when they are amplifying and studying the same region of DNA in each species?
They can identify it because there are unique sequences for each species. If you take a sample and find the DNA of it you can then compare it to the DNA’s of known bacteria to discover what bacteria the sample is from
1. Why is PCR used in the process of DNA sequencing?
It’s a technique that amplifies DNA by making a perfect temperature for primers and enzymes to make copies. With the millions of copies you have you can then code the DNA to figure out it’s sequence.
2. How can the DNA sequencing technique shown in the virtual lab be used to identify other classes of pathogens, such as viruses?
Extract DNA of virus from infected cell and run PCR. It will be the same process done with the bacterial DNA. You can also check symptoms. You can then use the sequenced DNA and compare it to the DNA of various viruses.
3. Explain how sequence data and information about
Describe the limitations of traditional methods of identifying bacteria.
Traditional methods include judging by phenotypic characteristics. This could be a problem if two bacteria looked similar because they could easily be confused.
Summarize the goal of each of the six parts of the lab.
Sample Prep
First we need to extract the DNA from the bacterial wall
PCR Amplification
Create millions of copies of the initial DNA
PCR Purification
Filter out DNA from primers and enzymes
Sequencing Prep
Run more PCR to make copies of DNA at various lengths
DNA Sequencing
Sequence machine runs gel electrophoresis to identify nucleotides and determine sequence.
Sequence Analysis
Computer determines full DNA sequence which can be run and compared.
Explain how fluorescent markers help determine a nucleotide sequence.
Each nucleotide is assigned a certain color.
Conclusion
1 How can scientists identify specific bacteria when they are amplifying and studying the same region of DNA in each species?
They can identify it because there are unique sequences for each species. If you take a sample and find the DNA of it you can then compare it to the DNA’s of known bacteria to discover what bacteria the sample is from
1. Why is PCR used in the process of DNA sequencing?
It’s a technique that amplifies DNA by making a perfect temperature for primers and enzymes to make copies. With the millions of copies you have you can then code the DNA to figure out it’s sequence.
2. How can the DNA sequencing technique shown in the virtual lab be used to identify other classes of pathogens, such as viruses?
Extract DNA of virus from infected cell and run PCR. It will be the same process done with the bacterial DNA. You can also check symptoms. You can then use the sequenced DNA and compare it to the DNA of various viruses.
3. Explain how sequence data and information about