Serology and BLOOD. Serology The study of body fluids Examples… 1. Blood 2. Semen 3. Saliva 4....
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Transcript of Serology and BLOOD. Serology The study of body fluids Examples… 1. Blood 2. Semen 3. Saliva 4....
Serology and Serology and BLOODBLOOD
SerologySerology
The study of body fluidsThe study of body fluids Examples…Examples…1.1. BloodBlood
2.2. SemenSemen
3.3. SalivaSaliva
4.4. SweatSweat
5.5. Fecal matterFecal matter
6.6. urineurine
Blood TriviaBlood Trivia
% of body weight % of body weight contributed to bloodcontributed to blood
# of liters of blood in a # of liters of blood in a human bodyhuman body
Amount of blood loss Amount of blood loss that would cause that would cause DEATHDEATH
Amount of blood loss Amount of blood loss would incapacitate a would incapacitate a humanhuman
On average, 8 % of total body
5-6 liters in men 4-5 liters in females
40 percent blood volume loss, internally or/and externally, is required to produce irreversible shock (death). That would be 2000 ml
1.5 liters
Composition of bloodComposition of blood White and red blood cellsWhite and red blood cells Plasma (AKA serum Plasma (AKA serum
when re\moved from when re\moved from body)body)
Antibodies (proteins Antibodies (proteins involved in an immune involved in an immune response/attack)response/attack)
Antigens (proteins on cell Antigens (proteins on cell membrane that cause an membrane that cause an immune response)immune response)
ProteinsProteins Enzymes (peroxidase)Enzymes (peroxidase) PlatletsPlatlets
3 questions to ask when a maroon/red liquid is 3 questions to ask when a maroon/red liquid is found at the scenefound at the scene
Is it Blood?Is it Blood? Is it Human?Is it Human? Whose is it?Whose is it?
Is it Blood?Is it Blood?
Luminol TestLuminol Test Reaction of peroxidase in Reaction of peroxidase in
blood with luminol and a blood with luminol and a base base
forms a glowing forms a glowing substance when test is substance when test is positivepositive
Works to 3 x 10Works to 3 x 10-9-9 dilution dilution Does not destroy bloodDoes not destroy blood
Is it Blood?Is it Blood?
Phenolphthalein/ Kastle Myer Phenolphthalein/ Kastle Myer TestTest
Reaction of Peroxidase (an Reaction of Peroxidase (an enzyme in blood to break enzyme in blood to break down Hdown H22OO22) reacts with H) reacts with H22OO2 2
Then solutionis reacted with Then solutionis reacted with phenolphthalein, a positive test phenolphthalein, a positive test shows up pink…just like CSIshows up pink…just like CSI
However, it also turns pink in However, it also turns pink in the presence of potatoes or the presence of potatoes or horseradish, so care must be horseradish, so care must be taken at the scene.taken at the scene.
Is it HUMAN???Is it HUMAN???
Immuno AssayImmuno Assay Reaction between antibodies and antigensReaction between antibodies and antigens Positive test when blood clots formPositive test when blood clots form Can be used to determine if blood is Can be used to determine if blood is
another specific mammalanother specific mammal Is also used for blood typingIs also used for blood typing
Whose is it?Whose is it?
DNA analysis DNA analysis and use of and use of electrophoresis electrophoresis must be done…..must be done…..
But that’s But that’s another unitanother unit
Blood SpatterBlood Spatter
What can blood spatter TELL US?What can blood spatter TELL US?
ORIGINORIGIN Type of weaponType of weapon Direction blood was travelingDirection blood was traveling Location & movement of victim and Location & movement of victim and
assailantassailant # of blows/gun shot wounds# of blows/gun shot wounds
Passive Vs. ActivePassive Vs. Active
Passive vs. Active Blood LossPassive vs. Active Blood Loss
PassivePassive Due to gravityDue to gravity Dripping, oozing, poolsDripping, oozing, pools Low velocityLow velocity Usually large circular Usually large circular
dropsdrops Passive termsPassive terms::
• Drops • Drip patterns • Pools • Clots
ProjectedProjected An external or internal force An external or internal force
acting on bloodacting on blood Spurting or gushing bloodSpurting or gushing blood Impact spatterImpact spatter Can occur after death before Can occur after death before
blood coagulatesblood coagulates Sources: stabbing, Sources: stabbing,
beating,arterial spurt, cast off, beating,arterial spurt, cast off, expirated blood ( FROM expirated blood ( FROM LUNGS THROUGH LUNGS THROUGH MOUTH/NOSE),MOUTH/NOSE),
Med-high velocityMed-high velocity
Velocity of spatterVelocity of spatterRelative Relative speedspeed
Size of Size of spatterspatter
(diameter)(diameter)
Actual speedActual speed SourceSource
High velocityHigh velocity < 1 mm< 1 mm 100 ft/sec100 ft/sec Gun shotGun shot
sneezesneeze
Medium Medium velocityvelocity
1-4 mm1-4 mm 25 ft/sec25 ft/sec BeatingBeating
StabbingStabbing
Cast offCast off
Low velocityLow velocity 4-6 mm4-6 mm 5 ft/sec5 ft/sec Passive lossPassive loss
Passive vs. ActivePassive vs. Active
Arterial SpurtArterial Spurt
Spatter & VelocitySpatter & Velocity
Transfer Blood StainsTransfer Blood Stains
TRANSFER BLOODSTAINSTRANSFER BLOODSTAINS
A transfer bloodstain is created when a wet, bloody surface comes in contact with a secondary surface.
A recognizable image of all or a portion of the original surface may be observed in the pattern,as in the case of a bloody hand or footwear.
Transfer bloodstains can be further subdivided into; • Contact bleeding • Swipe or Smear • Wipe
• Smudge
TARGET SURFACE TEXTURETARGET SURFACE TEXTURE
The type of surface the blood strikes The type of surface the blood strikes affects the amount of resulting affects the amount of resulting spatter,including the size and spatter,including the size and appearance of the blood drops.appearance of the blood drops.
Blood droplets that Blood droplets that strike a hard smooth strike a hard smooth surface, like a piece surface, like a piece of glass, will have of glass, will have little or no distortion little or no distortion around the edge.around the edge.
Blood droplets that strike a surface with slight texture ( linoleum flooring) take on a slightly different appearance
Scalloping will occur around the edge of the blood droplets
Surfaces such as wood or concrete are Surfaces such as wood or concrete are distorted to a larger extent.distorted to a larger extent. Notice the spikes Notice the spikes
and secondary spatter presentand secondary spatter present
Blood Spatter VocabBlood Spatter Vocab
SplashesSplashes
SmearSmear
TrailsTrails
PoolsPools
Projected blood loss, Projected blood loss, having a tailhaving a tail
Left by bleeding Left by bleeding victim, touching victim, touching objectsobjects
Passive, left by victim Passive, left by victim when moving from when moving from location to locationlocation to location
Due to heavy passive Due to heavy passive bleeding, in one placebleeding, in one place
More VocabMore Vocab
SpikesSpikes
Void patternVoid pattern
ExsanguinationExsanguination
Cast OffCast Off
Poky, out juttings on a Poky, out juttings on a blood dropblood drop
Absence of blood in an area of Absence of blood in an area of spatterspatter
Indicating that an object or a Indicating that an object or a person was in the path of the person was in the path of the bloodblood
Bleeding to death, Bleeding to death, a.k.a. hypovolemic a.k.a. hypovolemic shockshock
Blood released or thrown from a
blood-bearing object in motion
Cast OffCast Off
Which way did it go?Which way did it go? You can determine the You can determine the
direction that blood and other direction that blood and other liquids are traveling using tails liquids are traveling using tails and satellites.and satellites.
Tail: long projection on one Tail: long projection on one side of a dropside of a drop
Satellite: small droplets Satellite: small droplets Tails and satellites will always Tails and satellites will always
be on the front side of the be on the front side of the drop, or the side the blood drop, or the side the blood was moving towardwas moving toward
DirectionalityDirectionality
Look for tails……….Look for tails……….
Look for tails….Look for tails….
Point of ConvergencePoint of Convergence
POINT OF CONVERGENCEPOINT OF CONVERGENCE
The common point, on a 2 dimensional surface, over which the directionality of several bloodstains can be retraced.
Once the directionality of a group of stains has been determined, it's possible to determine a two dimensional point or area for the group of stains.
By drawing a line through the long axis of a group of bloodstains the point of convergence can be determined. Where the lines of the group of stains intersect one anotherthe convergence point can be established.
Point OF ORIGINPoint OF ORIGIN
Analyze THIS ……….Analyze THIS ……….
With BLOOD Timing is With BLOOD Timing is everything…everything…
Blood begins to clot from 3 to 15 min. Blood begins to clot from 3 to 15 min. outside of the bodyoutside of the body
If blood is dark shiny and jelly-like it is less If blood is dark shiny and jelly-like it is less than 60 minutes O.O.T.B.than 60 minutes O.O.T.B.
If the blood is clotted and contracts away If the blood is clotted and contracts away from plasma the blood is 2-5 hrs oldfrom plasma the blood is 2-5 hrs old
This is just a rough guideThis is just a rough guide