ForensicSpot9 modules
Forensic Serology
The identification and characterisation of blood and body fluids in forensic casework: from presumptive and confirmatory blood tests through species origin, ABO and other blood-group systems, semen, saliva, and other biological fluids, to modern mRNA and microbiome methods, bloodstain ageing, and the laboratory workflow that preserves DNA downstream.
- 54hours
- 30topics
- 9modules
Module 16 hrs3 topics
Foundations of Forensic Serology
What serology means in a forensic context, its place in the laboratory workflow alongside DNA analysis, the composition and properties of blood, and the history of the discipline from the first precipitin tests to immunochromatographic strips.
Start module- Scope and History of Forensic SerologyForensic serology applies the science of biological fluids to legal investigations, connecting a century of blood-group chemistry to today's rapid detection kits and DNA workflows.12 min
- Composition and Properties of BloodBlood is a complex tissue of cells, proteins, and dissolved molecules, each with distinct forensic significance as they age, dry, and respond to environmental insult.13 min
- Order of Testing and DNA PreservationThe sequential testing protocol, from presumptive screening through confirmatory serology to DNA extraction, is designed to answer each question with the least possible destruction of the evidence beneath it.15 min
Module 26 hrs4 topics
Presumptive Tests for Blood
The chemical and enzymatic screening tests that indicate the possible presence of blood. Mechanism of action, sensitivity, specificity, common false-positive sources, and the operational context in which each test is deployed.
Start module- Kastle-Meyer TestThe Kastle-Meyer test uses reduced phenolphthalein to exploit haemoglobin's peroxidase-like activity, producing a vivid pink colour that serves as the leading presumptive test for blood at crime scenes worldwide.12 min
- Leucomalachite Green TestThe leucomalachite green test is a presumptive colour test for blood that turns green on oxidation by haemoglobin, offering a useful complement to the Kastle-Meyer test with a distinct colour endpoint and similar sensitivity.11 min
- Luminol and FluoresceinLuminol produces blue chemiluminescence and fluorescein produces yellow-green fluorescence when activated by trace haemoglobin, enabling investigators to locate bloodstains that are invisible to the naked eye, including stains that have been cleaned or diluted.13 min
- Bluestar and HemastixBluestar is a reformulated luminol-based reagent designed to reduce DNA damage during latent-blood searching, while Hemastix is a peroxidase-strip dipstick for rapid point-of-care blood screening, each suited to different scene and laboratory contexts.13 min
Module 36 hrs4 topics
Confirmatory Tests for Blood and Species of Origin
Tests that specifically identify human blood by detecting haemoglobin derivatives or unique proteins: crystal methods, immunological confirmatory assays, and the immunological techniques used to determine whether blood is of human or animal origin.
Start module- Teichmann and Takayama Crystal TestsTwo classic microcrystal tests that confirm blood by growing haematin (Teichmann) or haemochromogen (Takayama) crystals from a stain, distinguishing blood from its look-alikes under the microscope.12 min
- RSID-Blood and ABAcard HemaTraceLateral-flow immunochromatographic tests that confirm human blood in minutes by detecting haemoglobin with anti-human antibodies, offering high sensitivity and field-deployable simplicity compared with classical crystal tests.12 min
- Species of Origin: Precipitin and Ouchterlony TestsAntibody-antigen precipitation tests that identify whether blood at a crime scene is human or animal, from the historic ring precipitin test to the gel-diffusion Ouchterlony method that can distinguish species by the arcs they form.13 min
- Anti-Human Haemoglobin ELISA and Modern ImmunoassaysELISA and related immunoassay formats that quantify or detect human haemoglobin with exceptional sensitivity, and how their sensitivity, cross-reactivity profiles, and reporting requirements compare with classical precipitin and lateral-flow methods.13 min
Module 46 hrs4 topics
Blood Group Systems in Forensic Context
The ABO, Rh, and MNS antigen systems and the secretor status trait: their biological basis, forensic history and discriminating power, typing methods on stains, and the transition from classical serology to DNA-based individualisation.
Start module- ABO System: Biology and Forensic HistoryKarl Landsteiner's discovery of ABO blood groups transformed both medicine and forensic science, giving investigators their first reliable biological marker to type crime-scene stains before DNA existed.14 min
- ABO Typing on Stains: Absorption-Elution and InhibitionDried bloodstains and other body-fluid traces cannot be typed by direct agglutination. Forensic serologists use absorption-elution and absorption-inhibition techniques to assign ABO groups to crime-scene stains, each with distinct principles, protocols, and failure modes.14 min
- Secretor Status and Its Forensic ValueAbout 80% of people secrete ABO blood-group antigens into body fluids such as saliva and semen, a trait controlled by the FUT2 gene. Secretor status multiplied the discriminating power of pre-DNA forensic serology and remains relevant alongside modern DNA methods.14 min
- Rh, MNS, and Other Blood Group SystemsBeyond ABO, the Rh and MNS blood group systems provided additional class-level discrimination in pre-DNA forensic serology, though their antigens degrade faster on dried stains and their forensic use declined sharply with the rise of DNA profiling.14 min
Module 56 hrs3 topics
Semen Identification
The full toolkit for identifying semen in forensic samples: screening tests, microscopic confirmation of spermatozoa, protein-based assays, and the interpretation of azoospermic or degraded samples.
Start module- Acid Phosphatase Screening for SemenAcid phosphatase secreted by the prostate gland is the oldest reliable screening marker for semen, detectable by colorimetric and fluorescent tests long before DNA became routine.14 min
- Spermatozoa Identification by MicroscopyMicroscopic examination of spermatozoa, especially after Christmas tree staining, remains the definitive identification of semen and requires careful attention to cell morphology, counting conventions, and the interpretive challenges of azoospermia.13 min
- p30/PSA and RSID-SemenProstate-specific antigen (PSA/p30) and the RSID-Semen immunochromatographic strip are the two principal protein-based confirmatory tests for semen, each with defined sensitivity limits and characteristic behaviour on samples from vasectomised and azoospermic donors.14 min
Module 66 hrs4 topics
Saliva, Urine, and Other Body Fluids
Identification methods for biological fluids other than blood and semen: saliva, urine, sweat, faeces, vaginal fluid, and the forensically important distinction between menstrual blood and peripheral blood.
Start module- Saliva Identification: Amylase and RSID-SalivaSalivary amylase is the primary biochemical marker used to detect saliva on forensic exhibits, supported by the RSID-Saliva immunochromatographic assay. This topic covers Phadebas and RSID testing, sensitivity and specificity considerations, and best practices for collection and reporting.12 min
- Urine and Sweat IdentificationUrine and sweat are encountered in forensic casework across sexual assaults, drug investigations, and touch-DNA scenarios on fabric. This topic covers creatinine, urea, and UV fluorescence for urine; the RSID-Urine assay; and the challenges of sweat identification where no specific confirmatory test exists.12 min
- Vaginal Fluid and Faecal Material IdentificationVaginal fluid and faecal material are identified in sexual assault and other casework using glycogen-based tests, ferning, RSID-Vaginal Mucosa, and microscopic and chemical tests for faecal origin. This topic covers the specific assays, their limitations, and why correct identification matters for interpreting mixed biological stains.12 min
- Menstrual Blood versus Peripheral BloodDistinguishing menstrual blood from peripheral (venous or arterial) blood is a forensic challenge with direct implications for sexual assault and injury investigations. This topic covers fibrinolytic activity, matrix metalloprotease MMP-10, D-dimer, and the current limitations of available assays.12 min
Module 76 hrs2 topics
Modern Body-Fluid Identification: mRNA and Microbiome
Post-DNA advances that use messenger RNA expression profiles and microbial community signatures to identify body fluids with greater specificity and to work on highly degraded or mixed samples where protein-based tests fail.
Start module- mRNA Profiling for Body Fluid IdentificationTissue-specific messenger RNA expression patterns allow forensic analysts to identify which body fluid deposited a stain, even when proteins and conventional markers have degraded. This topic covers the target genes, platforms, and validation requirements behind mRNA-based fluid identification.13 min
- Microbiome-Based Body Fluid IdentificationEach body fluid harbours a distinctive microbial community whose composition can be read from metagenomics data to identify fluid type, even when human protein and mRNA markers have failed. This topic covers the 16S rRNA sequencing approach, fluid-specific microbial signatures, and the current state of validation and admissibility.13 min
Module 86 hrs3 topics
Ageing of Bloodstains
How blood changes over time once deposited, and the scientific methods proposed to estimate how old a bloodstain is, with frank discussion of the current evidentiary limitations.
Start module- Physical and Chemical Changes in Ageing BloodstainsAs a bloodstain ages, haemoglobin oxidises through a predictable colour sequence from red to brown to black, driven by substrate, humidity, UV light, and temperature in ways that make universal ageing models elusive.13 min
- Spectroscopic Methods for Bloodstain AgeingUV-Vis reflectance, near-infrared, and Raman spectroscopy can track haemoglobin oxidation states in ageing bloodstains with objective precision, but validation gaps and environmental confounders mean these methods remain research tools rather than validated casework standards in most jurisdictions.13 min
- mRNA and microRNA Approaches to Stain AgeRNA degrades in a partly predictable pattern after blood leaves the body, and microRNA species such as miR-let-7b have been studied as molecular markers of bloodstain age, but highly variable degradation rates across individuals and environments keep this a research technique rather than a validated casework method.15 min
Module 96 hrs3 topics
Bloodstain Pattern Introduction, Quality, and Court
A bridge module covering the serological analyst's interface with bloodstain pattern analysis, the quality-assurance framework governing the discipline, and how serology findings are interpreted and communicated in court.
Start module- Introduction to Bloodstain Pattern RecognitionA practical primer on how serologists and bloodstain pattern analysts divide their roles, and why documenting patterns before any chemical test is non-negotiable.12 min
- Quality Assurance in Serology LaboratoriesHow ISO 17025 accreditation, reagent controls, proficiency testing, and international guidelines keep forensic serology results reliable and legally defensible.12 min
- Serology Evidence in Court: Interpretation and TestimonyHow forensic serologists move from laboratory findings to courtroom testimony, interpreting probabilistic results correctly and avoiding the logical fallacies that have undermined serology evidence in landmark cases.15 min