Forensic Serology Lecture Notes (copy)

Serology

The study of physiological (bodily) fluids.

Recognition in Forensic Blood Evidence

Identifying where blood is located.

Search in Forensic Blood Evidence

Locating evidence effectively.

Collect in Forensic Blood Evidence

Gathering blood samples.

Package in Forensic Blood Evidence

Properly storing the samples.

Identification in Forensic Blood Evidence

Determining the type of blood.

Individualization in Forensic Blood Evidence

Ascertaining whose blood it is.

Reconstruction in Forensic Blood Evidence

Analyzing how blood arrived at the scene.

Steps of forensic blood evidence processing

Recognition, Identification, Individualization, and Reconstruction.

Karl Landsteiner

Discovered blood types A, B, and O in 1901.

Alfred von Decastello

Contributed to blood research by discovering type AB in 1902.

Rh Protein

Identified by Landsteiner and Alex Wiener in 1937.

Percy Oliver

Established a blood donor service in 1922.

Total blood volume in adults

Approximately 4–6 liters.

Blood composition

55% plasma, 45% red blood cells, <1% white blood cells and platelets.

Red Blood Cells (RBCs)

Transport oxygen; lifespan is approximately 120 days.

Plasma

The liquid component of blood, constituting about 55% of its volume, carries salts and proteins.

White Blood Cells (WBCs)

Fight infection; lifespan is approximately 10 days.

Platelets

Help with clotting; lifespan is approximately 5 days.

Structure of Red Blood Cells

About 5 million in a drop of blood, only have a nucleus when young, made in bone marrow.

Structure of White Blood Cells

About 8000 in a drop of blood; produced in bone marrow and other organs.

Structure of Platelets

About 250,000 per drop.

Antigens

Found on the RBC surface (A, B).

Antibodies

Found in plasma (Anti-A, Anti-B); bivalent with 2 reactive sites.

Agglutination

Clumping of red blood cells due to antibody-antigen interactions.

Erythrocytes

Another name for red blood cells.

Leukocytes

Another name for white blood cells.

Thrombocytes

Another name for platelets.

Blood components

Blood consists of plasma, red blood cells, white blood cells, and platelets.

Primary function of RBCs

Transport oxygen throughout the body.

Primary function of WBCs

Fight against infections and help in immune response.

Function of Platelets

Facilitate blood clotting and hemostasis.

Adult male blood volume

Is typically around 5-6 liters.

Adult female blood volume

Is typically around 4-5 liters.

Blood plasma composition

About 90% water, also contains salts and various proteins.

Lifespan of RBCs

Approximately 120 days before they are recycled by the body.

Lifespan of WBCs

Approximately 10-12 days depending on the type.

Lifespan of platelets

Approximately 5-7 days before they are removed from circulation.

Function of Antigens

Determine blood type and trigger immune responses.

Function of Antibodies

Bind to specific antigens to neutralize or remove them.

Blood type A

Has A antigens and Anti-B antibodies.

Blood type B

Has B antigens and Anti-A antibodies.

Blood type AB

Has A and B antigens, no antibodies.

Blood type O

Has no antigens and both Anti-A and Anti-B antibodies.

Role of the immune system

To identify and attack foreign substances, including blood antigens.

Importance of serology in forensics

Helps in the identification and analysis of bodily fluids at crime scenes.

Blood type compatibility

Essential for safe blood transfusions to prevent agglutination.

Blood component volume percentages

55% plasma and 45% cellular components (RBCs, WBCs, platelets).