1. SEROLOGY

2. SEROLOGY
The science of body fluid identification and characterization (typically blood, semen, saliva, and urine)

3. Serology
Examination of blood, semen, saliva, and urine through the use of presumptive tests and confirmatory tests

4. Serology starts with the suspect’s or victim’s clothing, weapons, and other evidentiary items

5. Cuttings or swabbings are taken from evidence

6. Blood Blood is composed of
cells – red blood cells (erythrocytes), white blood cells (leukocytes), and platelets; cells make up 45% of blood content
plasma – fluid portion of un-clotted blood; plasma makes up 55% of blood content
Where is DNA?
white blood cells

7. Blood Red blood cells – about 5 million per microliter
White blood cells – 2,000 to 7,000 per microliter; present in much smaller concentration than red blood cells, but this is where we get DNA from
Red blood cells have no nucleus and, therefore, no nuclear DNA

8. Blood - “possibly”
Presumptive Test: a chemical test that uses color change to detect the possible presence of blood
Fast Reaction
Not Specific

9. Phenolphthalein Test
Hemoglobin (red blood cell protein that transports oxygen) possesses peroxidase-like activity that oxidizes phenolphthalein yielding a bright pink color.
hemoglobin + phenolphthalein reagent + hydrogen peroxide = bright pink color
Presumptive test for blood, but cannot rule out other sources – false positives (e.g. copper, broccoli, fruit juice)
Not human specific (e.g. reacts with animal blood)

10. Hemastix Test Reacts with blood hemoglobin
Peroxidase-like activity
Positive reaction in seconds
Not human specific
Hemoglobin

11. Hemastix Test

12. Presumptive Tests for Blood
Presumptive Screening Tests For Blood
Test
Indicator
Sensitivity
Comment
Benzidine
Blue color
Carcinogen
Tetra-methyl-benzidine
+ + +
Probable carcinogen
o-Tolidine
Dark green
Phenolphthalein
Pink color
+ +
Safe
Leucomalachite green
Green color
Relatively safe
Luminol
Fluorescence
* tests are not human specific

13. Luminol is used by forensic scientists to detect trace amounts of blood left at crime scenes.

14. Blood Enhancement with Luminol/Fluorescein
Drain grate in
holding cell – blood visualized with luminol

15. Blood Enhancement with Luminol/Fluorescein
Bloody
shoeprint
and other
bloodstains
on flooring

16. Blood Identification
Confirmatory test for blood uses the formation of crystals to indicate the presence of blood.
Takayama Crystals or Hemochromogen Crystals

17. Origin Test
The Ouchterlony test uses antibody reactions to determine if blood is human. 

18. Semen Semen composed of
spermatozoa – the male reproductive cell; 100 million cells per ml; 2.5 – 6 ml per ejaculate (meaning each ejaculate contains up to 600 million sperm cells)
seminal fluid – fluid portion of semen that contains acid phosphatase and PSA (prostate specific antigen)
acid phosphatase – 400 X more concentrated in semen than in other body fluids
PSA or p30 – unique to semen
Where is DNA?
spermatozoa (sperm cells)

19. Semen - “possibly” Acid Phosphatase
Presumptive Test: a chemical test that uses color change to detect the possible presence of semen
Acid Phosphatase
Blue color change indicates presence of acid phosphatase – “possibly semen”

20. Semen Identification p30 test
Confirmatory/Origin Determination Test: an antibody reaction test that indicates the presence of human semen through the formation of a precipitant band on the test device C T S
Positive
Test
Negative
p30 test

21. Semen Identification
Spermatozoa – Christmas tree staining; stains heads of sperm cells red and tails green allowing for microscopic visualization
Prostate Specific Antigen (p30) – unique to seminal fluid; PSA card
Christmas Tree Staining.

22. Saliva - “possibly” Where is DNA?
Starch Agar is an all-purpose medium which is flooded with Gram's iodine. The iodine reacts with starch to form a dark blue-colored complex. Any clear area around the sample indicates the breakdown of starch due to the presence of amylase, an enzyme found in saliva.
Where is DNA?
epithelial cells (cheek skin cells)

23. After serology testing, samples are prepared for DNA typing
Purple top - EDTA
After serology testing, samples are prepared for DNA typing

24. Masks and Caps
Items commonly used by bank robbers to disguise themselves
DNA can be obtained from the saliva left on the mask or from the sweatband of a baseball cap

25. Chewing Gum
A ring of thieves would steal cars to use as their “get-a-way” vehicles
DNA extracted from gum (epithelial cells) taken from the ignition switch of the stolen cars matched one of the suspects
He confessed and led police to the others involved

26. Bandages
Bank robber covered his face with bandages to disguise himself
He threw them away outside the bank
DNA recovered from the adhesive portion matched the suspect

27. Serology Protocols Date issued and revision number Scope, background
Equipment
Controls (+ and -)
Precautions – work surface, PPE, one item
QC procedures – (i.e. test ALS with +)
Analytical procedure
Limitations
Safety
References
Signatures

28. Serology Protocols – Positive/Negative Controls
Positive control - a known sample that indicates equipment/reagents are working properly
Negative control – tests for contamination of reagents and materials