Serology and Blood Analysis

What is serology?

The examination and analysis of body fluids, including saliva, semen, urine, and blood.

What was the importance of forensic serology from 1950 to the late 1980s?

It was a crucial part of lab procedures before the development of DNA techniques.

What is plasma?

The fluid portion of the blood, making up 55% of its volume.

What are erythrocytes?

Red blood cells responsible for oxygen distribution.

What role do leukocytes play in the blood?

They are white blood cells responsible for cleaning the system of foreign invaders.

What are thrombocytes?

Also known as platelets, they are responsible for blood clotting.

What is serum?

The liquid that separates from blood when a clot is formed.

What does the ABO blood group system indicate?

It is based on the presence of A and/or B antigens on red blood cells.

What is the Rh factor?

A protein that may be present on red blood cells; positive if present, negative if absent.

What is agglutination?

Clumping of red blood cells that occurs if blood types with different antigens are mixed.

What does type O blood signify regarding alleles?

It is considered a recessive gene represented as OO.

How can disputed paternity be resolved using blood group systems?

By analyzing the blood types of suspected parents and offspring.

What initial questions should be addressed regarding an unknown stain at a crime scene?

Is it blood? Is it human blood? Whose blood is it?

What is the purpose of the Kastle-Meyer Color Test?

To determine the presence of blood through a color change reaction.

What is a precipitin test used for?

To differentiate between human and animal blood by forming a precipitate.

What factors led to the increased reliance on DNA analysis over blood types in forensics since the 1990's?

DNA analysis provides extremely accurate individualization results.

What is blood spatter evidence?

The study of blood patterns produced under various conditions from applied forces.

What conditions affect the shape of a blood droplet?

Volume of blood, angle of impact, velocity, height, and texture of the target surface.

What is the angle of impact in bloodshed terminology?

The angle at which blood strikes a target surface.

What is a drip pattern in blood?

Blood indicating higher volume and deposition on a vertical surface.

What is the difference between contact stains labeled as swipe and wipe?

Swipe involves transferring wet blood onto a surface without blood; wipe occurs when a non-bloody object alters a wet bloodstain.

What does blood spatter interpretation provide regarding the scene of bloodshed?

It can reveal the distance from the blood source, point of origin, movement of the person, and number of blows or shots.

What is the area of convergence in blood spatter analysis?

The point where lines drawn from blood droplets intersect, indicating the area of origin.

What is the distinction between class evidence and individual evidence in blood analysis?

Blood type is class evidence, while DNA analysis provides individual evidence if determined.