forensics blood quiz

willow spring high school

three questions when examining blood stain

is stain actually blood, what species, what type of blood if human

role of RBC

most abundant, antigens, produced in bone marrow, contains hemoglobin

role of WBC

work with immune system, contains nucleus DNA

tests to determine if stain is blood

kastle-meyer (PINK), hemastix (GREEN), luminol

main chemical in kastle-meyer test

phenophthalein PINK

test used to determine if human or not

preciptin test (antibodies)

importance of using luminol

very sensitive, indicates old blood or tiny drops, doesn't interfere with DNA

where are antibodies found

proteins formed by WBCs carried in plasma based upon what blood type you are (your antigen)

your blood type

your antigen

Type A blood contains these antigens and antibodies

A antigens, anti-B antibodies

type AB blood contains these antigens and antibodies

A+B antigens, no antibodies

clumping

agglutination

mom- A dad- O

A or O

O positive

most common

AB negative

least common

angle of impact formula

sin(angle) = width/length

satelites

little dots away from splatter

low velocity has this diameter

3mm or larger

medium velocity hsa this diameter

1-3 mm

high velocity has this diameter

1 or less mm

cast-off spatter

blood swinging off a weapon

expiratory blood spatter

from lungs/sinus

blood spatter on smooth surface

uniform, circular, small, smooth edges

blood spatter on medium rough surface

crenelated edges with spines

blood spatter on rough surface

parent drop with satelites

serology

study of blood

where antigens are found

protein markers that determine blood type in RBCs