M

2. SEMEN
-This is a viscid whitish fluid of the male reproductive tract
consisting of spermatozoa suspended in
The secretion of accessory glands.
PARTS OF SEMEN:
A. Seminal Fluid
B. Formed cellular elements which includes:
1. Spermatozoa or sperm cells
2. Epithelial cells
3. Crystals of choline and lecithin to 3.5 cc is the normal
quantity of seminal fluid in single ejaculation.
A healthy young man releases 400 to 500 million
spermatozoa in a single ejaculation.

3. CASES WHEREIN EJACULATION
HAS NO SPERMATOZOA
1. Males suffering from aspermia
A. ASPERMIA
- A condition wherein males have no spermatozoa
at all in their seminal fluid.
2.Males suffering from oligosperm
B. OLIGOSPERM
- Condition whereby males have abnormally low
sperm counts or with few spermatozoa.

4. WHERE SEMEN AND SEMINAL
STAINS CAN BE FOUND:
Semen can be found fresh in :
1. Vaginal contents of the victim
2. Rectal contents of the victim
Semen can be found as wet or dried conditions/secretion on:
1. Hair
2. Skin around the genitals
Semen can be found as dry stain on:
1. Underclothing
2. Bed clothing

5. COLLECTION,
PRESERVATION, PACKING
AND TRANSIT OF SPECIMEN:
1. Seizure of apparel must be done as soon as possible.
2. In packing a clothing apparel worn by a victim, there should be no
friction between the apparel and the stain.
3. Specimen should not be rolled for transit.
4. Smaller objects like hair should be placed in a test tube and corked.
5. Specimen should be thoroughly dried before packing.
6. Fluid semen should be placed in a test tube. It may be preserved by
a few drops of 10% solution of formalin during hot weather.

6. SEMEN AND SEMINAL
STAINS EXAMINATION
There are four examinations for seminal stains or seminal fluid
in the form of stains, namely:
1. Physical Examination
2. Chemical Examination
A. Florence test
B. Barberio’s test
C. Acid-phosphatase test
3. Microscopic Examination
4. Biological Examination

7. I. PHYSICAL EXAMINATION
SEMINAL STAINS:
a) Semen when dry gives stiff, starchy feeling to the
cloth and produces slight deeping of the color with
the disappearance of the odor.
b) Seminal stains exhibits fluorescence under the
ultraviolet light.
c) Grayish white, sometimes yellowish stain which is
typical of seminal fluid.
d) They have an appearance or outline of a contour
map.
e) May have a reddish tint in case of old man.

8. II. CHEMICAL
EXAMINATION
A. FLORENCE TEST
-This is only a preliminary test, presence of spermatozoa confirms
the presence of seminal stains.
REAGENT/CHEMICALS: Florence reagent (made of 1.6 g KI and
grams I2 in 30cc water.
PROCEDURE: Cut a portion of the stain and divide into small bits then
soak in saline solution. Transfer into a slide, tease and evaporate the fluid.
Add a drop of Florence reagent and cover with cover slip. Examine
under the microscope.
VISIBLE OF POSITIVE RESULT: Crystals of choline periodide
that are dark brown, rhombic or needle shaped that occurs singly or in
crossed even grouped in clusters.

9. B. BARBERIO’S TEST
- This test is almost specific for human semen. Seminal stain
as old as 6 years old are said to respond to this test.
REAGENT/CHEMICALS: Saturated aqueous or alcoholic solution
of picric acid.
PROCEDURE: Soak a piece of stained materials in a 2.5%
solution of trichloroacetic acid for one hour on a test tube. Centrifuge
the test tube. Get the clear liquid part and add to an equal amount of a
saturated aqueous or alcoholic solution of picric acid on a glass slide.
Observe under the microscope.
VISIBLE OR POSITIVE RESULT: Crystals that are slender
yellowish, rhomboid needles with obtuse angle or appear as avoid
crystals (these crystals are made of spermine picrate).

10. C. ACID-PHOSPHATASE TEST
- This test is the best way to locate and at the same time
characterize a seminal stain. This test replaced the Florence test in reliability
and was shown to be specific for human and higher apes. The test is based
fundamentally upon the extraordinarily high acid phosphatase content of
human male ejaculation.
REAGENTS/CHEMICALS: 23 g sodium chloride; 0.5cc of glacial acetic
acid; 2 g of sodium acetate trihydrate in 90cc water; a suspension of 30 mg
anthraquione-1-diazonium chloride and 50gms of calcium-1-alphanaphtyl
phosphate in 1cc of 1% aerosol.
PROCEDURE: Treat the stained are in a water bath at pH 5 containing
alphanaphcyl phosphate as substrate and antraquinone 1- diozorium
chloride. Add the above reagents.
VISIBLE OR POSITIVE RESULTS:
Orange-red pigment.

11. III. MICROSCOPIC
EXAMINATION
- The chief purpose of which is to determine the presence of
spermatozoa. The identification of spermatozoa is at present the only
specific test for semen.
VISIBLE RESULT: SPERMATOZOA
- This is small object with a pear-shaped head, behind which is a
short neck and a tail about ten times as long as the head.
DETERMINATION OF SPERMATOZOA IN
FRESH SEMEN
1. Transfer a drop of specimen to a glass slide.
2. Add a drop of water or saline solution and cover with cover slip.
3. Examine under the microscope
4. Observe for the presence of spermatozoa.

12. DETERMINATION OF SPERMATOZOA IN
SEMINAL STAINS:
1. A small piece of material is teased on a slide in a drop of water.
2. Allow the smear to dry and then stain with LOFFLER’S
METHYLENE BLUE for a minute. Wash with water, dry and
examine under the microscope.
ELEMENTS WHICH MAY OBSTRUCT
DETECTION OF SPERMATOZOA
1. Nature of the fabric
2. Age of the stain
3. Conditions to which the stain was exposed before reaching the
laboratory.
4. Handling of the specimen.

13. IV. BIOLOGICAL EXAMINATION
-The test was proposed by Farnum in 1901. He injected human
semen to a rabbit from five to eight times at intervals of 6 to 8 days. The
serum obtained from the blood of the rabbit gave a precipitate with bite
recent and old emulsions of human semen.
-Hektoen and Rustinant showed that this serum is both specie
specific , i.e. it gives a positive reaction with human blood.
-The spermato – precipitin is of value in the identification of seminal
fluid in certain cases like for example bestiality where it may be desirable to
differentiate between the human seminal fluid from that of the animal.
LIMITATION:
-The bacteria action which produces disintegration of spermatozoa
in seminal stain is equally effective in decomposing or digesting the protein
constituents of semen that acts as the antigen – producing antibodies. Such
seminal stain with their protein constituents completely disintegrated cannot
possibly precipitin reaction.

14. OTHER STAIN OF MEDICO-
LEGAL INTEREST
1. Obstetrical and gynaecological stains
2. Excrements
a. Adults – yellowish brown and solid
b. Infant – greenish yellow
3. Paint stains
4. Rust stains
a. Rust – reddish-brown in color,
insoluble in water and soluble in diluted
acid resembles blood stains.

15. 5. Synthetic Dye Stains
a. Resembles old blood stain, but can be
recognized by treating with strong acid alkalis.
6. Mineral Stains
a. These are due to red paints containing
oxides of iron
7. Stains of Vegetable origin
a. Stain resembles blood. They may be
produced by fruit juices like mulberry and
mangosteen.