Forensic Serology: Blood Spatter 

The First Question

 

Before a forensic serologist devotes time to determining the area of origin and analyzing an entire crime scene, they must first answer the question, "Is this actually blood?" and if so, is it human in nature?

 

In order to determine whether a stain at a crime scene is blood, the scientist has a variety of presumptive tests to determine if a stain is blood. If the test is positive, analysis will continue, and a confirmatory test will be conducted in a laboratory.

 

The two most popular tests for determining the presence of blood are the Kastle-Meyer color test, and Luminol. The Kastle-Meyer test uses phenolphthalein and hydrogen peroxide to test an unknown liquid or bloodstain. The test is positive if the sample turns a deep pink color.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Luminol (C8H7N3O2) is a chemical test that utilizes an oxidation reaction in the hemoglobin of blood to produce chemiluminescence.  Luminol is widely known by the public thanks to its glorification within CSI shows in popculture.