Categories of bloodstains / DNA

Passive bloodstains

These ads drops created it formed by the firxd of gravity acting alone

Pool

This refers to a change in the shape and direction if bloodstain due to influence of gravity or movement of the object

Drop

Crested by the force of gravity

Drip

Caused by dripping blood

Transfer bloodstains

Is created when a wet and bloody surface comes in contact with a secondary surface

Semen

Refers to the body fluids produced by the male sex organ , amounting to 2.5 to 6.0 ml per ejaculation

Oligospermia

Who have an abnormally low sperm count this condition is called ?

Wet specimen

A drip of the fluid is placed on a glass slide to which a few drops of distilled water are added. This is then examined under a high powered microscope to determine the presence of sperm

Biological examination

This test is used to differentiate human from animal fluid

Deoxyribonucleic acid (DNA)

Is a molecule that contains the genetic information used in the development and functioning of known viruses and living organisms

Restriction fragment length polymorphism (RFLP,) Analysis

One of the first methods used in finding out genetics used for DNA profiling

Polymerase Chain reaction (PCR) Analysis

It identifies specific SNA sequence of interest wherein the DNA sample is denatured into separate individual strands. This method then replicate DNA into million fold in two hours or less

Short tandem repeats (STR) Analysis

Uses highly polymorphic regions with shorts repeated sequence it helps identify individual matches for in several control samples indicate relationship

Amplified fragment lengths polymorphism

This technique is faster than RFLP Analysis and uses PCR to amplify DNA samples. It relies on variable number tandem repeat. It is relatively cheaper and easier to set up and operate . Remain popular in developing countries