Blood Identification Flashcards
What is the difference between a presumptive and confirmatory test?
A presumptive test gives an indication of the identity of a substance, for example if it is blood, but is subject to false results. A confirmatory test is used to identify a subatance with certainty.
True or False:
With some presumptive tests, sensitivity can be increased by adding a drop of ethanol prior to reagent applicant (e.g. KM)
True
True or False:
The heme group of the hemoglobin molecule is an enzyme.
False
Most catalytic color tests for bodily fluids involve a two-step reaction where the
___________
is added first, then there is a brief pause where no color should be observed, followed by the addition of the
_________
Organic Chromogenic Agent, Oxidizer
What is the scientific name of the Takayama Test?
Hemocromagen Crystal
What is the scientific name of the McPhail’s Reagent Test?
Leucomalachite Green
What is the scientific name of the Kastle-Meyer Test?
Phenolphthalien
What is the scientific name of the Gentian Violet Test?
Leucocrytal Violet
True or False:
It is currently possible to reliably age a bloodstain by its color.
False
What type of crystals does the Teichmann test have?
Hematic chloride
What type of crystals does the Takayama test have
Hemochromagen crystals
Give 4 examples of presumptive tests for blood
Luminol, Phenolpthalin (KM), Leuco Crystal Violet, Tetramethylbenzidine (TMB)
Presumptive test for blood are________________________.
Neither mammal, human, or primate-specific
A substance that increases the rate of a chemical reaction without being used or permanently changed during the reaction.
Catalyst
False positive presumptive blood tests may be caused by
The oxygen in the air, Certain vegetables, Chemical Oxidants
Which of the following is true?
Hemoglobin is responsible for carrying oxygen
Hemoglobin is located in the red blood cells
Heme is a component of hemoglobin
All of the above
________
is a chemical reaction in which a substance gives up electrons when that substance interacts with oxygen, and
________
a chemical reaction in which a substance gains electrons.
Oxidation, reduction
True or False:
Blood in its natural state will absorb light and appear black in color when examined with an ALS.
True
Which of the following tests might be used to determine that a bloodstain was of human origin?
Amylase Test
Precipitin Test
Luminol
Kastle-Mayer
Precipitin Test
Presumptive blood tests are usually_____________________.
Sensitive
