SEMEN & SEMINAL STAINS.pptx

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1. SEMEN AND SEMINAL STAINS

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: Seizure of apparel must be done as soon as possible. In packing a clothing apparel worn by a victim, there should be no friction between the apparel and the stain. Specimen should not be rolled for transit. Smaller objects like hair should be placed in a test tube and corked. Specimen should be thoroughly dried before packing. 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: Physical Examination Chemical Examination A. Florence test B. Barberio’s test C. Acid-phosphatase test Microscopic Examination Biological Examination

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

8. II. CHEMICAL EXAMINATION 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 I 2 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 Transfer a drop of specimen to a glass slide. Add a drop of water or saline solution and cover with cover slip. Examine under the microscope Observe for the presence of spermatozoa.

12. DETERMINATION OF SPERMATOZOA IN SEMINAL STAINS: A small piece of material is teased on a slide in a drop of water. 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 Nature of the fabric Age of the stain Conditions to which the stain was exposed before reaching the laboratory. 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. - H ektoen 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 Obstetrical and gynaecological stains Excrements a. Adults – yellowish brown and solid b. Infant – greenish yellow Paint stains 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.