Presumptive Blood Test Kit
by Innovating Science

The presumptive blood test is one of, if not the, most commonly performed test in forensic science. It is extremely versatile and easy, allowing it to be performed directly at a crime scene, or in the lab.

It is also known as the Kastle-Meyer test, and it uses phenolphthalein to detect the possible presence of hemoglobin. The test relies on the peroxidase-like properties of hemoglobin to act as a catalyst to start the process of oxidizing the phenolthalein. By adding hydrogen peroxide, the reaction can be sped up, turning the tip of the swab bright pink.

One of the biggest drawbacks of this test however, is that there are other substances that share the same peroxidase-like properties of hemoglobin. So just because there is a positive result, it does not mean that the sample is actually blood; it just -could- be blood.

This kit includes MSDS sheets for all of the included chemicals, as well as teacher’s guide with background information and the experiment procedures.

Also included are:

• 2x 25mL of Phenolphthalein
• 2x 25mL of Ethyl alcohol
• 1x 50mL of Hydrogen peroxide
• 50 cotton swabs
• 5 positive control blood strips, from a non-human blood source