6.5.2 DNA Profiling

• What is DNA profiling used for in forensics?

  Identify individuals
• DNA profiling involves identifying individuals based on unique DNA sequences
• Steps in the DNA profiling process

  1️⃣ DNA Extraction

  2️⃣ PCR Amplification

  3️⃣ Gel Electrophoresis

  4️⃣ Profile Interpretation
• Short tandem repeats (STRs) are amplified during PCR amplification
• Gel electrophoresis separates DNA fragments by size
• What is the purpose of comparing banding patterns in DNA profiling?

  Identify individuals
• DNA profiling is a forensic technique used to identify individuals based on their unique DNA sequences
• DNA is extracted from biological samples such as blood, saliva, or hair
• What does PCR create multiple copies of in DNA profiling?

  STRs
• Gel electrophoresis results in a unique banding pattern
• In DNA extraction, cell lysis involves breaking open cells to release DNA
• What is used to precipitate DNA in the final step of DNA extraction?

  Ethanol
• DNA extraction can be performed on blood, saliva, or hair samples
• PCR amplification is a technique used to amplify specific regions of DNA
• Steps in PCR amplification

  1️⃣ Denaturation

  2️⃣ Annealing

  3️⃣ Extension
• At what temperature does denaturation occur in PCR?

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

  DNA polymerase
• PCR amplification is a step in DNA profiling that increases the quantity of specific DNA regions
• Which method is used to separate DNA fragments by size in DNA profiling?

  Gel electrophoresis
• In DNA profiling, the banding pattern is compared to databases during interpretation
• DNA profiling involves comparing a unique banding pattern to identify individuals
• Steps in DNA profiling and their purposes

  1️⃣ DNA Extraction: Isolate DNA from a biological sample

  2️⃣ PCR Amplification: Increase the quantity of specific DNA regions

  3️⃣ Gel Electrophoresis: Separate DNA fragments by size

  4️⃣ Profile Interpretation: Compare the profile to databases
• What is DNA profiling used for?

  Identifying individuals
• Steps involved in DNA profiling

  1️⃣ DNA Extraction

  2️⃣ PCR Amplification

  3️⃣ Gel Electrophoresis

  4️⃣ Profile Interpretation
• PCR is used in DNA profiling to amplify specific DNA regions (STRs)
• DNA fragments are separated by size using gel electrophoresis
• What is the first step in DNA extraction?

  Cell lysis
• PCR amplification involves denaturation at 94-98°C to separate DNA strands
• Primers bind to single-stranded DNA during the annealing phase of PCR
• What is the optimal temperature for DNA polymerase to synthesize new strands during PCR?

  72°C
• Restriction enzymes cut DNA at specific recognition sites
• EcoRI produces sticky ends, which are useful for cloning
• What is the purpose of gel electrophoresis?

  Separate DNA by size
• Steps in gel electrophoresis

  1️⃣ Sample loading

  2️⃣ Separation

  3️⃣ Visualization
• DNA probes are labeled with radioactive or fluorescent markers for detection
• STR probes target specific STR loci for individual identification
• How do DNA probes enhance the accuracy of DNA profiling?

  Highlight regions amplified by PCR
• DNA probes target complementary
• DNA probes are labeled with radioactive or fluorescent markers for detection.