Forensic serology

1. FORENSIC SEROLOGY

2. Human Blood Animal Blood
Blood Cells Red blood cells, white blood cells, and
platelets are the cellular components of
the human blood.
Most animals comprise red blood cells,
white blood cells, and platelets. Animals
with a closed circulatory system comprise
hemocytes.
Blood Group Humans comprise ABO blood group and
Rh blood group.
Animals comprise different blood groups
Respiratory Pigments Hemoglobin is the respiratory pigment
of humans and other vertebrates
Hemoglobin, haemerythrin, haemocyanin,
and chlorocruorin are the four types of
respiratory pigments in invertebrates.
Blood Color Human blood is red in color. Red, blue, green, and pink are the colors of
the blood in animals.
Red Blood Cell Antigens A, B, and Rhesus antigen are the three
types of antigens present in the red
blood cells of humans.
Red blood cells of animals may contain
different types of antigens.
Red Blood Cell Nucleus and
Organelles
Humans and other mammals do not
have a nucleus and organelles in red
blood cells.
Animals other than mammals have a nucleus
and organelles in red blood cells.
White Blood Cells Humans have five types of white blood
cells.
Different animals have different types of
white blood cells.

3. SPECIES OF ORIGIN
Most assays for species
identification
 immunochromatographic assays
 precipitation-based assays
include ring assays, Ouchterlony
assays, and crossed-over
immunoelectrophoresis.

4. Immunochromatographic assays
OBTI and
the ABAcard
HemaTrace®
Human Hemoglobin
Protein
RSID™-
Blood
Identification of
Human Glycophorin A
Protein

5. precipitation-
based assays
include ring
assays
RING ASSAY PROCEDURE:
 Sample preparation and extraction
 Controls (positive and negative)
 Loading of antibody and samples
 Immunodiffusion reaction

6. OUCHTERLONY
ASSAY
• Cross over gel diffusion is a technique where antigens and
antibodies are left to react overnight on a gel plate.
• Agglutination / precipitation is recorded by bands that
are formed between wells.
OUCHTERLONY ASSAY PROCEDURE:
 Sample preparation
 Controls • Positive (known serum) • Negative (extraction
blank) • Substrate controls (extraction of substrate from
unstained area)
 Agarose gel preparation
 Loading antibodies and samples
 Immunodiffusion reaction

8. Immuno electrophoresis
• But cross-over gel diffusion takes a
lot of time and the little sample that
we have will get evaporate by then.
• Electrophoresis helps to speed up
the process/diffusion.
• We perform horizontal
electrophoresis using an agarose
gel.
• Antigens and Antibodies are plotted
at 2 different ends of the agarose
plate.
• Multiple samples can be tested at
the same time.

9. Immuno-electrophoresis
• The sample load (Ammonia extract)
must face the cathode (black end) and
the antisera must face the anode (red
end).
• Use filter paper/tissue paper wicks
moistened in tank buffer to connect
the gel plate with the tank buffer.
• The usual electrophoresis run is set at
150V, 15mA for 20 minutes.