6.5.2 DNA Profiling

• DNA profiling is a forensic technique used to identify individuals based on unique DNA
• Steps involved in DNA profiling

  1️⃣ DNA Extraction

  2️⃣ PCR Amplification

  3️⃣ Gel Electrophoresis

  4️⃣ Profile Interpretation
• What are Short Tandem Repeats (STRs) used for in DNA profiling?

  Amplifying specific DNA regions
• PCR amplification increases the quantity of specific DNA regions in DNA profiling.
• Amplified DNA fragments are separated by size using gel electrophoresis
• What is the first step in DNA extraction?

  Cell lysis
• In DNA extraction, DNA is precipitated using ethanol
• PCR amplification exponentially increases the quantity of DNA with each cycle.
• The first step in DNA profiling is DNA extraction
• What is the role of PCR in DNA profiling?

  Amplify specific DNA regions
• Steps involved in DNA profiling

  1️⃣ DNA Extraction

  2️⃣ PCR Amplification

  3️⃣ Gel Electrophoresis

  4️⃣ Profile Interpretation
• Match the step in DNA profiling with its purpose:

  DNA Extraction ↔️ Isolate DNA from a biological sample

  PCR Amplification ↔️ Increase the quantity of specific DNA regions

  Gel Electrophoresis ↔️ Separate DNA fragments by size

  Profile Interpretation ↔️ Compare the profile to databases
• What is DNA profiling used for in forensic science?

  Identifying individuals
• What is DNA profiling used for?

  Identifying individuals
• PCR amplification uses STRs to increase the quantity of specific DNA regions
• Gel electrophoresis separates DNA fragments based on their size.
• What is the purpose of DNA extraction in DNA profiling?

  Isolate DNA
• PCR amplification increases the quantity of specific DNA regions called STRs
• Match the process with its purpose in DNA profiling:

  DNA Extraction ↔️ Isolate DNA from a biological sample

  PCR Amplification ↔️ Increase the quantity of specific DNA regions

  Gel Electrophoresis ↔️ Separate DNA fragments by size

  Profile Interpretation ↔️ Compare the profile to databases for identification
• What is the first step in DNA extraction?

  Cell lysis
• DNA precipitation uses ethanol to precipitate DNA
• Steps involved in PCR amplification

  1️⃣ Denaturation

  2️⃣ Annealing

  3️⃣ Extension
• At what temperature does denaturation occur during PCR amplification?

  94-98°C
• During annealing, primers bind to single-stranded DNA
• Which enzyme synthesizes new DNA strands during the extension step of PCR?

  DNA polymerase
• PCR amplification exponentially increases the quantity of DNA with each cycle.
• What is the purpose of restriction enzyme digestion?

  Cut DNA at specific sequences
• Restriction enzymes recognize and cleave DNA at their recognition sites.
• EcoRI produces sticky ends when it cleaves DNA at GAATTC.
• Which restriction enzyme produces blunt ends?

  SmaI
• Restriction enzyme digestion is useful in genetic engineering and DNA analysis
• Smaller DNA molecules move faster through the gel matrix during gel electrophoresis.
• What is used to visualize DNA bands in gel electrophoresis?

  UV light
• What is the primary role of DNA probes in DNA profiling?

  Bind to specific DNA sequences
• DNA probes are labeled with radioactive or fluorescent markers
• Match the probe type with its target sequence:

  STR probes ↔️ Specific STR loci

  SNP probes ↔️ Single nucleotide polymorphisms

  Allele-specific probes ↔️ Specific alleles of genes
• What is the role of probes in DNA profiling?

  Enhance accuracy and speed
• DNA probes are labeled with radioactive or fluorescent markers for easy detection
• What is the purpose of DNA profiling?

  Identify individuals based on DNA
• Steps in DNA profiling

  1️⃣ DNA Extraction

  2️⃣ PCR Amplification

  3️⃣ Gel Electrophoresis

  4️⃣ Profile Interpretation