froensics blood/ serology

Hemoglobin

The iron-containing protein in red blood cells that carries oxygen throughout the body and gives blood its red color.

Agglutination

The clumping of red blood cells that occurs when incompatible blood types are mixed.

Blood spatter

The pattern that results when blood droplets are projected or dispersed through the air, revealing information about events at a crime scene.

Luminol

A chemical used in forensic testing that reacts with iron in blood to produce a blue glow in the dark.

Directionality

The path that a blood droplet travels through the air, determined by the shape of the stain.

Antibodies

Proteins in blood plasma that identify and attack foreign substances, such as incompatible blood antigens.

Plasma

The liquid portion of blood that carries cells, nutrients, hormones, and waste products throughout the body.

Serum

The clear fluid that remains after blood has clotted; contains antibodies but no clotting factors.

Antigens

Proteins on the surface of red blood cells that determine blood type (A, B, AB, or O).

Impact pattern

A bloodstain pattern created when a force is applied to a source of liquid blood.

Swipe pattern

A pattern created when a bloody object moves across a clean surface, leaving a smear in the direction of motion.

Void

An empty area within a blood spatter pattern indicating an object or person blocked the blood from hitting that surface.

Wipe pattern

A pattern created when an object moves through an existing wet bloodstain, altering its appearance.

Secretor

A person whose blood-type antigens are also found in other body fluids such as saliva, semen, or sweat.

Presumptive test

A preliminary test that indicates the possible presence of blood but does not confirm it without further testing.

Serology

The scientific study of blood and other body fluids, used in forensics to identify bodily fluids at crime scenes.

Type A blood

Blood type that possesses A antigens on its surface and can agglutinate when receiving type B blood.

Type AB blood

The universal recipient blood type, which can receive blood from all types but can only donate to type AB.

Precipitin test

A test used by forensic veterinarians to determine whether blood contains animal proteins rather than human proteins.