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ahmed alhindawe
ahmed alhindawe

Serology is the study of bodily fluids and is used in forensic science to identify fluids like blood, semen, and saliva found at crime scenes. Serology tests help determine what types of fluids are present and provide context about the crime. While DNA analysis can directly identify individuals, serology tests are faster, cheaper, and can exclude unnecessary DNA analysis. Serology tests identify proteins specific to different fluids and are less specific than DNA profiling, but help determine what samples need further DNA analysis. Blood identification specifically involves tests to detect blood, determine if it is human, and identify its blood group.

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Serology in Forensic Laboratories By: Karmel Al-Khaldi
Serology Serology: The study of bodily fluids. Serology in forensic science: Identification of body fluids such as: Blood Saliva Urine Semen in forensic laboratories to answer questions of interest to the legal system.
Serology in Forensic Science DNA analysis helps in direct individualization. Why serology?
Serology vs. DNA Analysis Serology Tests DNA Profiling Helps in identifying the source of DNA (type of body fluid) Determination of context of crime. E.g. Semen might indicate rape. Does not identify DNA source. Fast, efficient, and inexpensive. saves time and efforts by excluding unnecessary analyses. E.g. DNA profiling of non-human blood samples. Slower and expensive Identify proteins specific for body fluids Less specific: helps in identification Depends on nucleic bases in DNA specific for each individual More specific: helps in individualization
The Major Body Fluids Blood Semen Saliva Urine Sweat
The Major Body Fluids Blood Semen Saliva Urine Sweat
Blood Blood: a tissue composed of several types of cells in a matrix called plasma. Plasma: 90% water 10%: proteins (hemoglobin as one of the major constituents) urea amino acids carbohydrates organic acids fats steroid hormones inorganic ions
Blood in Forensic Labs Blood can be a good source of information for investigators in many ways. Examples: 1. Identification/individualization: determination of blood source. Biological Analysis Section 2. Detection of drugs and toxins. Toxicology and Drugs Section
Blood in Forensic Labs Identification of blood in forensic labs is performed by answering the following questions: 1. Is it blood? 2. Is it human (determination of species origin) 3. In which blood group is it classified?
Blood in Forensic Labs Identification of blood in forensic labs is performed by answering the following questions: 1. Is it blood? 2. Is it human (determination of species origin) 3. In which blood group is it classified?
Test for the Presence of Blood Question: Is there blood in the questioned sample? Reaction of a testing chemical with the hemoglobin present in blood. Answer: Reaction occurs: Yes: +ve result: there is blood. Reaction does not occur: No: -ve result: there is no blood. Positive test results (i.e. presence of hemoglobin) are indicated by: 1. Change to a certain colored form. 2. Emission of light of a specific wavelength.
Test for the Presence of Blood Benzidine test: used by the FLD in Jordan. +ve results indicated by a green-blue color. Gives +ve results for all iron-containing samples such as rust- contaning samples. (Benzidine is carcinogenic)
Large-scale Blood Tests In cases where: 1. The blood pattern or distribution is important. 2. The tested area is large and intricate. The testing chemical is sprayed onto the surface then emitted light is observed. E.g. on such chemicals: 1. Luminol 2. Fluorescein
Large-scale Blood Tests 1. Luminol in presence of hemoglobin gives blue- white to yellow green color (+ve result). Very sensitive to the presence of hemoglobin The blood pattern is visible for up to 30 min in dark.
Large-scale Blood Tests 2. Fluorescein preparation is similar to luminol: preparation contains a thickener. Why adding a thickener? Makes fluorescein stay on the surface better than luminol easy to use on walls and vertical surfaces.
Large-scale Blood Tests Flourescene must be illumionated at 450 nanometers via an alternate light source (ALS) to be seen. (goggles are used for safety purposes).
Tests for Human Blood In some forensic laboratories: after detecting the presence of blood, DNA analysis is applied directly. In Jordan: the biology section in the FLD performs a confirmatory test.
Species Origin Is the blood in the sample of human origin or not? Detection techniques depend on antigen-antibody reactions between: - Human blood (antigen) in the questioned sample - Human antiserum (antibody) the test reagent (Antibodies against plasma proteins)
Species Origin Answer: Yes: +ve result: blood is of human origin. No: -ve result: blood is NOT of human origin.
Blood Groups Blood groups are: 1. Genetically controlled 2. Invariant throughout a persons life Excellent for classification and possible inclusion or exclusion for legal purposes. ABO blood grouping system: best known. Used by forensic laboratories to narrow down the search group.
Blood Groups ABO blood grouping: Use antibodies against antigens on the surface of red blood cells. Results: as in the next table.
Serology Tests Specificity (Specific tests): the ability of a test to detect one specific substance. Sensitivity (Sensitive tests): The ability of a test to detect (sense) very small amounts of a substance(s).
Serology Tests 2 types of tests for serological analyses: 1. Presumptive tests: highly sensitive with less specificity for a particular substance. E.g. Benzidine can detect minute amounts of blood in samples but gives +ve result for all iron containing samples such as rust contaning samples. False ve: dangerous: lead to the exclusion of important blood samples. Positive control is used to avoid false ve All +ve results (including false +ve) are taken and we move to the next step (confirmatory test).
Serology Tests 2. Confirmatory tests: highly specific with less sensitivity to a particular substance. E.g. Test for determining species origin gives +ve results only when human blood present but inefficient in detecting very small amounts of human blood.

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  • 2. Serology Serology: The study of bodily fluids. Serology in forensic science: Identification of body fluids such as: Blood Saliva Urine Semen in forensic laboratories to answer questions of interest to the legal system.
  • 3. Serology in Forensic Science DNA analysis helps in direct individualization. Why serology?
  • 4. Serology vs. DNA Analysis Serology Tests DNA Profiling Helps in identifying the source of DNA (type of body fluid) Determination of context of crime. E.g. Semen might indicate rape. Does not identify DNA source. Fast, efficient, and inexpensive. saves time and efforts by excluding unnecessary analyses. E.g. DNA profiling of non-human blood samples. Slower and expensive Identify proteins specific for body fluids Less specific: helps in identification Depends on nucleic bases in DNA specific for each individual More specific: helps in individualization
  • 5. The Major Body Fluids Blood Semen Saliva Urine Sweat
  • 6. The Major Body Fluids Blood Semen Saliva Urine Sweat
  • 7. Blood Blood: a tissue composed of several types of cells in a matrix called plasma. Plasma: 90% water 10%: proteins (hemoglobin as one of the major constituents) urea amino acids carbohydrates organic acids fats steroid hormones inorganic ions
  • 8. Blood in Forensic Labs Blood can be a good source of information for investigators in many ways. Examples: 1. Identification/individualization: determination of blood source. Biological Analysis Section 2. Detection of drugs and toxins. Toxicology and Drugs Section
  • 9. Blood in Forensic Labs Identification of blood in forensic labs is performed by answering the following questions: 1. Is it blood? 2. Is it human (determination of species origin) 3. In which blood group is it classified?
  • 10. Blood in Forensic Labs Identification of blood in forensic labs is performed by answering the following questions: 1. Is it blood? 2. Is it human (determination of species origin) 3. In which blood group is it classified?
  • 11. Test for the Presence of Blood Question: Is there blood in the questioned sample? Reaction of a testing chemical with the hemoglobin present in blood. Answer: Reaction occurs: Yes: +ve result: there is blood. Reaction does not occur: No: -ve result: there is no blood. Positive test results (i.e. presence of hemoglobin) are indicated by: 1. Change to a certain colored form. 2. Emission of light of a specific wavelength.
  • 12. Test for the Presence of Blood Benzidine test: used by the FLD in Jordan. +ve results indicated by a green-blue color. Gives +ve results for all iron-containing samples such as rust- contaning samples. (Benzidine is carcinogenic)
  • 13. Large-scale Blood Tests In cases where: 1. The blood pattern or distribution is important. 2. The tested area is large and intricate. The testing chemical is sprayed onto the surface then emitted light is observed. E.g. on such chemicals: 1. Luminol 2. Fluorescein
  • 14. Large-scale Blood Tests 1. Luminol in presence of hemoglobin gives blue- white to yellow green color (+ve result). Very sensitive to the presence of hemoglobin The blood pattern is visible for up to 30 min in dark.
  • 15. Large-scale Blood Tests 2. Fluorescein preparation is similar to luminol: preparation contains a thickener. Why adding a thickener? Makes fluorescein stay on the surface better than luminol easy to use on walls and vertical surfaces.
  • 16. Large-scale Blood Tests Flourescene must be illumionated at 450 nanometers via an alternate light source (ALS) to be seen. (goggles are used for safety purposes).
  • 17. Tests for Human Blood In some forensic laboratories: after detecting the presence of blood, DNA analysis is applied directly. In Jordan: the biology section in the FLD performs a confirmatory test.
  • 18. Species Origin Is the blood in the sample of human origin or not? Detection techniques depend on antigen-antibody reactions between: - Human blood (antigen) in the questioned sample - Human antiserum (antibody) the test reagent (Antibodies against plasma proteins)
  • 19. Species Origin Answer: Yes: +ve result: blood is of human origin. No: -ve result: blood is NOT of human origin.
  • 20. Blood Groups Blood groups are: 1. Genetically controlled 2. Invariant throughout a persons life Excellent for classification and possible inclusion or exclusion for legal purposes. ABO blood grouping system: best known. Used by forensic laboratories to narrow down the search group.
  • 21. Blood Groups ABO blood grouping: Use antibodies against antigens on the surface of red blood cells. Results: as in the next table.
  • 22. Serology Tests Specificity (Specific tests): the ability of a test to detect one specific substance. Sensitivity (Sensitive tests): The ability of a test to detect (sense) very small amounts of a substance(s).
  • 23. Serology Tests 2 types of tests for serological analyses: 1. Presumptive tests: highly sensitive with less specificity for a particular substance. E.g. Benzidine can detect minute amounts of blood in samples but gives +ve result for all iron containing samples such as rust contaning samples. False ve: dangerous: lead to the exclusion of important blood samples. Positive control is used to avoid false ve All +ve results (including false +ve) are taken and we move to the next step (confirmatory test).
  • 24. Serology Tests 2. Confirmatory tests: highly specific with less sensitivity to a particular substance. E.g. Test for determining species origin gives +ve results only when human blood present but inefficient in detecting very small amounts of human blood.