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3: DNA Profiling

Restriction enzymes, recognition sequences, gel electrophoresis, and applications in DNA profiling.

LibreTexts reference: DNA Profiling and Techniques

True/False Statements About English Palindromes

Click to show True/False Statements About English Palindromes example problem
Which one of the following English words is NOT a palindrome?
 

Blood Typing Test Results

Click to show Blood Typing Test Results example problem

During a blood typing test, anti-A, anti-B, and anti-D antibodies are added to a blood sample along with a control. A visible reaction indicates the presence or absence of the corresponding antigens.
What would the test results look like for someone with O+ blood type?

 

HLA Genotype Inheritance (2 Markers, Black)

Click to show HLA Genotype Inheritance (2 Markers, Black) example problem

HLA genotyping serves as a key component in the field of immunogenetics. It is used for understanding individual variations in immune responses. This molecular technique identifies unique alleles on paired chromosomes. It's particularly vital in organ transplantation for matching donors and recipients. Finding a correct match reduces the chance for graft rejection.
A mother has a HLA genotype of A9,B6 on one chromosome and A1,B2 on the other chromosome.
The father has a HLA genotype of A8,B1 on one chromosome and A3,B3 on the other chromosome.
Which one of the following combinations is a possible genotype for their offspring?

 

HLA Genotype Inheritance (3 Markers, Color)

Click to show HLA Genotype Inheritance (3 Markers, Color) example problem

HLA genotyping serves as a key component in the field of immunogenetics. It is used for understanding individual variations in immune responses. This molecular technique identifies unique alleles on paired chromosomes. It's particularly vital in organ transplantation for matching donors and recipients. Finding a correct match reduces the chance for graft rejection.
A mother has a HLA genotype of A7,B7,C5 on one chromosome and A2,B9,C2 on the other chromosome.
The father has a HLA genotype of A6,B6,C7 on one chromosome and A4,B2,C3 on the other chromosome.
Which one of the following combinations is a possible genotype for their offspring?

 

Restriction Enzyme DNA Strand Products (10 Length, 3 Sites)

Click to show Restriction Enzyme DNA Strand Products (10 Length, 3 Sites) example problem

DNA Strand Question:
Examine the DNA strand shown below. The table highlights a specific portion of a much longer DNA molecule to focus on the region containing restriction sites.

AcvI ClaI AcvI ClaI AcvI
0 1 2 3 4 5 6 7 8 9 10

Two (2) distinct types of restriction enzyme recognition sites, AcvI and ClaI, are labeled at the top of this DNA segment.
Note: The dashes at both ends of the strand indicate that the next restriction site is far away and outside the visible region. Because this segment is part of a much larger molecule, any uncut or very large fragments will not travel into the gel and will appear to be stuck in the well.

Determine the sizes of the DNA bands that would appear on an agarose gel after digestion with AcvI only.
 

Restriction Enzyme DNA Fragment Products (13 Length, 3 Sites)

Click to show Restriction Enzyme DNA Fragment Products (13 Length, 3 Sites) example problem

DNA Fragment Question:Shown below is a short DNA fragment that is only 13 kb in length. This fragment has been isolated for restriction enzyme analysis.

PacI BcuI PacI BcuI PacI
0 1 2 3 4 5 6 7 8 9 10 11 12 13

Two (2) distinct types of restriction enzyme recognition sites, PacI and BcuI, are labeled at the top of this DNA segment.

Determine the sizes of the DNA bands that would appear on an agarose gel after digestion with PacI only.
 

Restriction Enzyme DNA Strand Products (16 Length, 4 Sites)

Click to show Restriction Enzyme DNA Strand Products (16 Length, 4 Sites) example problem

DNA Strand Question:
Examine the DNA strand shown below. The table highlights a specific portion of a much longer DNA molecule to focus on the region containing restriction sites.

SrfI MvnI SrfI MvnI SrfI MvnI SrfI
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Two (2) distinct types of restriction enzyme recognition sites, SrfI and MvnI, are labeled at the top of this DNA segment.
Note: The dashes at both ends of the strand indicate that the next restriction site is far away and outside the visible region. Because this segment is part of a much larger molecule, any uncut or very large fragments will not travel into the gel and will appear to be stuck in the well.

Determine the sizes of the DNA bands that would appear on an agarose gel after digestion with SrfI only.
 

Restriction Enzyme DNA Fragment Products (8 Length, 2 Sites)

Click to show Restriction Enzyme DNA Fragment Products (8 Length, 2 Sites) example problem

DNA Fragment Question:Shown below is a short DNA fragment that is only 8 kb in length. This fragment has been isolated for restriction enzyme analysis.

SlaI AgeI SlaI
0 1 2 3 4 5 6 7 8

Two (2) distinct types of restriction enzyme recognition sites, SlaI and AgeI, are labeled at the top of this DNA segment.

Determine the sizes of the DNA bands that would appear on an agarose gel after digestion with SlaI only.
 

Restriction Enzyme Overhang Sequences (6 Choices)

Click to show Restriction Enzyme Overhang Sequences (6 Choices) example problem

Restriction enzymes are proteins that cut DNA at specific sequences to produce fragments for further study. These enzymes are obtained from various types of bacteria and have the ability to recognize short nucleotide sequences within a larger DNA molecule.
The restriction enzyme we are focusing on is SspMI, which is derived from the bacterium Sporosarcina species M.
SspMI cuts the DNA sequence as follows: 5'-C|TAG-3', where the '|' indicates the cleavage site.
Based on this information, which one of the following sequences below corresponds to the overhang region of the DNA after cleavage by the restriction enzyme SspMI?

 

Restriction Enzyme Cleavage Types

Click to show Restriction Enzyme Cleavage Types example problem

Restriction enzymes are proteins that cut DNA at specific sequences to produce fragments for further study. These enzymes are obtained from various types of bacteria and have the ability to recognize short nucleotide sequences within a larger DNA molecule.
The restriction enzyme we are focusing on is SfuI and is obtained from the bacteria Streptomyces fulvissimus.
SfuI cuts the DNA sequence as follows: 5'-TT|CGAA-3' where the '|' indicates the cut location.
Based on this info, can you identify the type of cut this enzyme makes?

 

Restriction Enzyme Overhang Types

Click to show Restriction Enzyme Overhang Types example problem

Restriction enzymes are proteins that cut DNA at specific sequences to produce fragments for further study. These enzymes are obtained from various types of bacteria and have the ability to recognize short nucleotide sequences within a larger DNA molecule.
The restriction enzyme we are focusing on is NaeI and is obtained from the bacteria Nocardia aerocolonigenes.
NaeI cuts the DNA sequence as follows: 5'-GCC|GGC-3' where the '|' indicates the cut location.
Based on this info, can you identify the type of cut this enzyme makes?

 

Palindromic Sequence Matches

Click to show Palindromic Sequence Matches example problem

The following numbered sequences only contains half of a palindromic sequence.
Match the correct lettered sequence that would finish and replace the 'N's in the sequence to make them palindromes.
Letters will be used exactly once.

Your Choice Prompt
Drop Your Choice Here 1.  
5′–  G   N   N   N  –3′
Drop Your Choice Here 2.  
5′–  N   N   N   ,   G   C   C  –3′
Drop Your Choice Here 3.  
5′–  C   N   N   N   ,   C   C   G   G  –3′
Drop Your Choice Here 4.  
5′–  C   C   G   G   ,   N   N   N   G  –3′

Drag one of the choices below:

  • A.  
     C   G   G 
  • B.  
     G   C   C 
  • C.  
     C   C   G 
  • D.  
     G   G   C 
 

RFLP Paternity Testing Results (EASY, 3 Males)

Click to show RFLP Paternity Testing Results (EASY, 3 Males) example problem
The Question

Who is the father of the child?


Mother





























Child





























Male 1





























Male 2





























Male 3




























Background

Restriction Fragment Length Polymorphism (RFLP) is a molecular biology technique used to distinguish between closely related DNA samples. It's commonly employed in paternity tests, among other applications.

Disclaimer

In actual diagnostic processes, the results of RFLP for confirming paternity are often cited to provide a 99.9% accuracy level or higher. However, no test is foolproof. Legal confirmation may involve additional procedures and evaluations to ensure the integrity and admissibility of the test.

Instructions

Use the provided DNA gel profile to determine paternity. Each band in the gel corresponds to a DNA fragment. Fragments are inherited; thus, the child's DNA will have overlapping fragments with the true father.

 

RFLP Paternity Testing Results (HARD, 9 Males)

Click to show RFLP Paternity Testing Results (HARD, 9 Males) example problem
The Question

Who is the father of the child?


Mother









































































Child









































































Male 1









































































Male 2









































































Male 3









































































Male 4









































































Male 5









































































Male 6









































































Male 7









































































Male 8









































































Male 9








































































Background

Restriction Fragment Length Polymorphism (RFLP) is a molecular biology technique used to distinguish between closely related DNA samples. It's commonly employed in paternity tests, among other applications.

Disclaimer

In actual diagnostic processes, the results of RFLP for confirming paternity are often cited to provide a 99.9% accuracy level or higher. However, no test is foolproof. Legal confirmation may involve additional procedures and evaluations to ensure the integrity and admissibility of the test.

Instructions

Use the provided DNA gel profile to determine paternity. Each band in the gel corresponds to a DNA fragment. Fragments are inherited; thus, the child's DNA will have overlapping fragments with the true father.

 

RFLP Paternity Testing Results (MEDIUM, 5 Males)

Click to show RFLP Paternity Testing Results (MEDIUM, 5 Males) example problem
The Question

Who is the father of the child?


Mother

















































Child

















































Male 1

















































Male 2

















































Male 3

















































Male 4

















































Male 5
















































Background

Restriction Fragment Length Polymorphism (RFLP) is a molecular biology technique used to distinguish between closely related DNA samples. It's commonly employed in paternity tests, among other applications.

Disclaimer

In actual diagnostic processes, the results of RFLP for confirming paternity are often cited to provide a 99.9% accuracy level or higher. However, no test is foolproof. Legal confirmation may involve additional procedures and evaluations to ensure the integrity and admissibility of the test.

Instructions

Use the provided DNA gel profile to determine paternity. Each band in the gel corresponds to a DNA fragment. Fragments are inherited; thus, the child's DNA will have overlapping fragments with the true father.

 

RFLP Forensic DNA Analysis Results (EASY, 4 Suspects)

Click to show RFLP Forensic DNA Analysis Results (EASY, 4 Suspects) example problem
The Question

Which suspect left blood at the crime scene?


Victim



























Blood



























Suspect #1



























Suspect #2



























Suspect #3



























Suspect #4


























Background

Restriction Fragment Length Polymorphism (RFLP) is a molecular biology method used to differentiate between closely related DNA samples. It is often used in forensic investigations.

Disclaimer

In adherence to the principles of due process, all individuals in this exercise shall be presumed innocent until proven guilty beyond a reasonable doubt in a court of law.

Instructions

Examine the provided DNA gel profile to identify which suspect is responsible for leaving the blood sample. Each band in the gel signifies a DNA fragment. The killer's DNA will match with the blood sample found at the crime scene.

 

RFLP Forensic DNA Analysis Results (HARD, 9 Suspects)

Click to show RFLP Forensic DNA Analysis Results (HARD, 9 Suspects) example problem
The Question

Which suspect left blood at the crime scene?


Victim









































































Blood









































































Suspect #1









































































Suspect #2









































































Suspect #3









































































Suspect #4









































































Suspect #5









































































Suspect #6









































































Suspect #7









































































Suspect #8









































































Suspect #9








































































Background

Restriction Fragment Length Polymorphism (RFLP) is a molecular biology method used to differentiate between closely related DNA samples. It is often used in forensic investigations.

Disclaimer

In adherence to the principles of due process, all individuals in this exercise shall be presumed innocent until proven guilty beyond a reasonable doubt in a court of law.

Instructions

Examine the provided DNA gel profile to identify which suspect is responsible for leaving the blood sample. Each band in the gel signifies a DNA fragment. The killer's DNA will match with the blood sample found at the crime scene.

 

RFLP Forensic DNA Analysis Results (MEDIUM, 5 Suspects)

Click to show RFLP Forensic DNA Analysis Results (MEDIUM, 5 Suspects) example problem
The Question

Which suspect left blood at the crime scene?


Victim

















































Blood

















































Suspect #1

















































Suspect #2

















































Suspect #3

















































Suspect #4

















































Suspect #5
















































Background

Restriction Fragment Length Polymorphism (RFLP) is a molecular biology method used to differentiate between closely related DNA samples. It is often used in forensic investigations.

Disclaimer

In adherence to the principles of due process, all individuals in this exercise shall be presumed innocent until proven guilty beyond a reasonable doubt in a court of law.

Instructions

Examine the provided DNA gel profile to identify which suspect is responsible for leaving the blood sample. Each band in the gel signifies a DNA fragment. The killer's DNA will match with the blood sample found at the crime scene.

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