You asked: What are 2 examples of tests that can be done to detect blood at a crime scene?

Which two tests can be done at the crime scene to detect blood?

What are two examples of tests that can be done to detect blood at a crime scene? 1. Using a solution of luminol and hydrogen peroxide. The luminol solution decomposes after reacting to the hemoglobin in blood, hence the blue glow.

What methods are used to detect blood?

The detection of blood is usually based on one of three classes of methods.

  • Crystal tests.
  • Catalytic tests.
  • Instrumental methods.

How is blood detected at a crime scene?

Blood detection

To detect blood at a crime scene or in the laboratory, an array of tests can be used. The most publicized test by crime shows is the Luminol process in which a chemical is sprayed onto a surface where blood is suspected to be.

What is an example of a confirmatory test?

Confirmatory tests for blood include identification of blood cells under a microscope [Shaler, 2002], crystal tests such as the Teichman and Takayama tests [Shaler, 2002; Spalding, 2003], and ultraviolet absorption tests [Gaensslen, 1983].

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What is the benzidine test used for?

The benzidine test is most commonly used for the detection of blood in the feces, and was therefore singled out for investigation.

How can you test your blood at home?

A person can identify their blood type at home using a rapid blood typing kit. Using the kit requires a person to prick a finger with a needle. The kit comes with a card that contains chemicals known as reagents. These test for the presence of the antibodies and Rh factor.

What are the three types of testing used in analyzing blood spatter?

Bloodstains are classified into three basic types: passive stains, transfer stains and projected or impact stains. Passive stains include drops, flows and pools, and typically result from gravity acting on an injured body.

How is blood used in criminal investigations?

Once doctors differentiated blood into distinct types, they could use that information to safely perform blood transfusions. Furthermore, forensic scientists can use that information to exculpate people suspected of some types of crimes, and they can use it to help determine the paternity of children.

What is preliminary blood test?

The location of faint and invisible blood stains and the preliminary identification of visible stains have long been performed by means of the benzidine test, supplemented less frequently by other catalytic’color tests such as the leuco-malachite green and the phenolphthalin tests, and the luminescent 3- …

How do presumptive blood tests work?

Presumptive tests react with the hemoglobin of all blood (human and animal) to catalyze the oxidation of a chromogenic compound, which produces a color change [25]. A positive reaction will result in the identification of the sample as possibly blood but not necessarily human blood.

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