The document discusses the analysis of semen in the context of forensic science, detailing its composition, morphology, and examination methods. It emphasizes the significance of semen analysis in assault cases and outlines various tests, including preliminary and confirmatory methods, to identify and analyze seminal stains. The document also covers the biological characteristics of semen and the importance of detecting sperm cells in various forensic contexts.

1. Maharishi Dayanand University
, Rohtak
Deptt. Of Forensic Science
Topic - Semen Analysis
Submitted To - Ravi Sir (R.S.)
Submitted By - Akash
2322

2. Contents:-
1.Introduction
2.Morphology
3.Composition
4.Examination
5.Forensic significence

3. SEMEN
• It is male’s body fluid containing procreative haploid
cells i.e., spermatozoa and originated from seminal
vesicle.
• Semen, also known as seminal fluid, is a thick, whitish
fluid that contains sperm and other secretions.
• It is composed of cellular portions and fluid portions.
• It is fluid with faint yellow colour and characteristic
odour c/d seminal odour.
• A typical ejaculation contains 2-5 ml of semen,160
million sperms.
• No. of spermatozoa = 50,000 to 3,50,000/ml

4. SEMEN
Typical Ejaculation -
• Seminal fluid -
1. Medium for ejaculation
2. Enzymes and other proteins
3. Acid phosphatase, Prostate Specific Antigen and
semalogenin.
• Sperm Cells - Spermatozoa.

5. Biological Characteristics of Semen -
• Semen is an extremely good source of DNA.
• Not all semen stain contain sperm
 Vasactomy - block sperms from being ejaculated.
 Semen still produced
 DNA typing probably not possible.
 Infertililty

6. Morphology of Sperm -
• Sperm cell can be divided into 3 parts;
1. Head - It contains nucleus and surrounded anteriorly by
acrosome.
2. Mid piece - It contains mitochondria that provide energy
for the tail movement.
3. Tail - It executes that propel the sperm.

7. Composition of Human Semen -

8. Composition of Human Semen -

9. Examiation Of Seminal Stain -
1. Preliminary test -
 Physical examination
 Chemical examination
2. Confirmatory test -
 Microscopic examination
 Christmas Tree Test
Physical Examination Of Semen
stain
 Include Visual Examination.
 To naked eye seminal stains
generally appear translucent or
opaque spots, at times with
yellowish tint and darker border
depending on colour and
thickness of substrata, which, if
absorbent, also acquire stiffness
due to dried semen.

10. Examiation Of Seminal Stain -
Chemical Examination
Florence test.
 For detection of choline (seminal origin)
 Basis: Choline is detected in this method.
 Procedure: A few drops of watery solution of the
stain is extracted and taken on a slide and a drop
of Florence reagent (8%) W/V solution of Iodine
in water containing 5% W/V of Potassium Iodide)
is poured & allowed to mix slowly under a cover
slip. Dark brown crystals of choline periodide,
generally needle shaped, formed with a few
minutes. Non-specifics & false negative results
are common.

11. Examiation Of Seminal Stain -
Chemical Examination
Barberio's test.
 Basis: Detection of Spermine (Prostate Origin )
 Procedure: A few drops of Berberio’s reagent
when added to spermatic fluid produces
crystals of sperm in picrate (needle shaped, &
of yellow colour). • For various valid reasons,
like non-specificity and lack of reproducibility,
the florence and berberio’s tests have not been
accepted universally.

12. Examiation Of Seminal Stain -
Chemical Examination
Acid Phoshatase test.
The Acid phosphate test is one of the best known and most widely employed techniques for
the purpose of identification of semen. This test is adopted because of high acid
phosphatase activity of semen.
Thus by applying this test a suspected azoospermic or Vasectomized person who is a
suspect of sexual offence may be identified. Stability of acid phosphatase activity in seminal
stain depends on temperature. If the stain is exposed to sunlight The acid phosphatase
activity is slowly reduced and if the stain is heated at 60C for 5 min. this Activity is
completely destroy.
The enzyme acid phosphatase of semen hydrolyses the calcium alpha-napthyl phosphoric
acid that Liberate as alpha naphthol. This couple with the age forming material to give a
purple colour.

13. Examiation Of Seminal Stain -
Confirmatory tests:
Microscopic examination: -
Demonstrable sperm in full size and shape is confirmatory test
for presence of human semen in sample. Age of sperm. 24 –
48 hours (in vitro). up to 72 hours (in utero)
The Microscopic detection of the Seminal stains is based in
morphology of spermatozoa.
Microscopic detection of spermatozoa. Cloth pieces from
different stains are taken in 0.5 ml of 0.01 N HCL in small test
tubes placed in a beaker containing water. After sonication for
5 minutes the extracts and the cloth pieces are transferred to
separate micro scope slides and cloth pieces delicately teased
with a needle. Threads are removed and the residual liquid is
gently evaporated to dryness. Residue obtained is stained
haematoxylin and eosin.

14. Examiation Of Seminal Stain -
Confirmatory tests:
Christmas Tree Test -
The Christmas Tree Stain is a microscopic technique
that uses two dyes to identify sperm cells in a slide:
Nuclear Fast Red: Stains sperm heads red and the
acrosomal cap pink
Picroindigocarmine: Stains sperm tails and epithelial
membranes green
The resulting color pattern makes sperm cells easy to
distinguish under a microscope.

15. Forensic Significance-
 Semen analysis is very important in assault cases as
it is very Useful for detection of semen in cloths.
 Isolation and identification of seminal stain found on
various suspected are asuch as cloths, bed sheet,
pillow, blanket, etc.
 Analysis of various protein present in semen or
seminal stain.
 Seminal stains are examined generally in rape
cases, Sodomy, Bestiality, Buccal coitus and in cases
of Sexual perversions.
 Detection of sperm cell in Vagina and other body
parts.
 Feacal matter examination.

16. References:-
https://www.slideshare.net/slideshow/semen-
analysis-96484002/96484002
https://www.ncbi.nlm.nih.gov/books/NBK279008/
table/benign-prstate-dsrdr.T.the_composition_o/
https://epgp.inflibnet.ac.in/epgpdata/uploads/