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PROTOCOL 02 // DNA & BIOLOGICALS

Forensic Serology & DNA Profiling

CALIBRATING EVIDENCE SENSORS...

INFINITE FORENSICS
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DOSSIER #IF-DOM-02
PROTOCOL 02 // DNA & BIOLOGICALS

Forensic Serology & DNA Profiling

Biological Fluid Identification, STR Multiplexing & Genetic Kinship

"Blood leaves a trace; DNA leaves an indelible genetic signature. The human genome never lies."

The biochemical detection of physiological stains (blood, semen, saliva, sweat, touch cells) and genetic characterization via 16 to 24 loci Short Tandem Repeats (STR) to establish individual identity or kinship.

CORE INTELLIGENCE
VERIFIED SYLLABUS
EXHIBIT CODE:IF-DISC-002
PRIMARY PROTOCOL:Section 45 IEA / BSA Standards
INSTRUMENT TIME:Active Bench Casework
INDUSTRY OUTLOOK:High Vocational Demand
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CORE FORENSIC PRINCIPLE

Foundational Admissibility Law

Genetic Polymorphism: Human Short Tandem Repeats (STRs) vary uniquely in length across individuals while being strictly inherited in Mendelian fashion from biological parents.

Judicial Standing: High statistical weight (1 in trillions) with full Section 45 IEA and CrPC Section 53A statutory recognition for sexual assault and homicide investigations.
SCIENTIFIC & EMPIRICAL BASIS

Analytical Methodology

Two-stage testing: Presumptive catalytic color tests (Kastle-Meyer, Luminol) followed by confirmatory protein tests (Takayama/Teichmann crystals) and capillary electrophoresis DNA sizing.

  • Differential extraction separating epithelial vs sperm DNA fractions
  • 28-cycle PCR amplification of 24 CODIS / European standard STR loci
  • Product rule probability and Likelihood Ratio (LR) calculation
STANDARD OPERATING CASWORK WORKFLOW

How An Examiner Investigates This Evidence

From scene cordoning to laboratory instrumentation and final deposition.

01STAGE 01

Catalytic Screening & Hemin Detection

Presumptive Kastle-Meyer oxidation and Luminol chemiluminescence to detect trace hemoglobin peroxidase activity.

02STAGE 02

STR Multiplex PCR Amplification

Thermal cycling with fluorescent primers to produce billions of copies of 16-24 Short Tandem Repeat loci.

03STAGE 03

Capillary Electropherogram Sizing

Laser-excited fluorescent migration measuring allele size in base pairs to generate an infallible judicial profile.

Primary Laboratory Instruments & Software

Official instrumentation deployed across accredited FSLs & independent crime labs.

1Applied Biosystems 3500xl Genetic Analyzer (24-Capillary CE)
2Thermal Cyclers (PCR) with Multi-Dye Fluorescent Detection
3QuantStudio Real-Time PCR (qPCR) for Human DNA Quantitation
4Automated Magnetic Bead DNA Extraction Workstations (QIAGEN / Promega)
5GeneMapper ID-X STR Genotyping Software
EVIDENCE VAULT EXPLORATION

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#02
Forensic Serology & DNA Profiling
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