Blood Identification

Question 1

What is the difference between a presumptive and confirmatory test?

Answer 1

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.

Question 2

True or False:
With some presumptive tests, sensitivity can be increased by adding a drop of ethanol prior to reagent applicant (e.g. KM)

Answer 2

True

Question 3

True or False:
The heme group of the hemoglobin molecule is an enzyme.

Answer 3

False

Question 4

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
_________

Answer 4

Organic Chromogenic Agent, Oxidizer

Question 5

What is the scientific name of the Takayama Test?

Answer 5

Hemocromagen Crystal

Question 6

What is the scientific name of the McPhail’s Reagent Test?

Answer 6

Leucomalachite Green

Question 7

What is the scientific name of the Kastle-Meyer Test?

Answer 7

Phenolphthalien

Question 8

What is the scientific name of the Gentian Violet Test?

Answer 8

Leucocrytal Violet

Question 9

True or False:
It is currently possible to reliably age a bloodstain by its color.

Answer 9

False

Question 10

What type of crystals does the Teichmann test have?

Answer 10

Hematic chloride

Question 11

What type of crystals does the Takayama test have

Answer 11

Hemochromagen crystals

Question 12

Give 4 examples of presumptive tests for blood

Answer 12

Luminol, Phenolpthalin (KM), Leuco Crystal Violet, Tetramethylbenzidine (TMB)

Question 13

Presumptive test for blood are________________________.

Answer 13

Neither mammal, human, or primate-specific

Question 14

A substance that increases the rate of a chemical reaction without being used or permanently changed during the reaction.

Answer 14

Catalyst

Question 15

False positive presumptive blood tests may be caused by

Answer 15

The oxygen in the air, Certain vegetables, Chemical Oxidants

Question 16

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

Answer 16

All of the above

Question 17

________
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.

Answer 17

Oxidation, reduction

Question 18

True or False:
Blood in its natural state will absorb light and appear black in color when examined with an ALS.

Answer 18

True

Question 19

Which of the following tests might be used to determine that a bloodstain was of human origin?
Amylase Test
Precipitin Test
Luminol
Kastle-Mayer

Answer 19

Precipitin Test

Question 20

Presumptive blood tests are usually_____________________.

Answer 20

Sensitive