Biological Evidence Flashcards
Sources of biological material (8)
blood
semen
saliva
urine
hair, bone, teeth, tissue
what crimes involving fluids 5
SA
assault
homicide
burglaries
desecrations
process of examination
recognition
identification
individualization
serology
the study of bodily fluids using specific antigen and serum antibody reactions
secretors
80% of population have blood antigens A and B
types of bodily fluids (4)
urine
saliva
semen
blood
what is urine
water secreted by the kidneys
tests for urine
Azostix: detects urease
Jaffe test: detects creatinine
what is saliva
99.5% water, 0.5% mucus etc.
tests for saliva
Phadebas test, Procion red amylopectin test: detect a-Amylase activity.
what is semen
seminal fluid
tests for semen
UV
APase
Fast Blue B dye
How is semen individual
DNA
how many rapes per hour
78
?/10 rape victims are female
9
what to collect in a rape case (7)
clothing
bedding
fingernail scrapings
hair
blood
urine
semen
what is blood
mix of cells, enzymes, proteins, inorganic substances
blood components
55% plasma (water+wastes, salts, ions, etc)
rest is ctyes
erythrocytes
red blood cells. no DNA. contain hemoglobin
leukocytes
white blood cells. primary cells of the immune system. produce anti body’s
thrombocytes
platelets. clot the blood.
how is blood type determined
antigens found on RBC’s, antibodies produced by WBC’s
universal donor
O-
universal acceptor
AB+
how many blood sub types are there
100
what determines + or - blood
Rh factor
how to test is it blood
Oxidizable colorless chemical+ an oxidizing agent catalyzed by hemoglobin
luminol
fluorescent with hemoglobin
Kastle-Meyer test
PHTH turns bright pink with blood
Teichmann Crystal test
if it’s human it will form brown visible crystals under the microscope
Takayama Crystal test
if it’s human it will form pink needle-shaped crystals under the microscope
Precipitin Test
animal blood will form a coagulated band at interception with human blood
things to consider with blood spatter (5)
surface texture
direction of travel
angle of impact
stain convergence lines
point of origin
