Often investigators will also use a combination of Phenolphthalein and O-Tolidine Presumptive Blood Tests to indicate the presumptive presence of blood. Phenolphthalein is one of the most commonly used chemicals in the field and forensics laboratory to indicate the presence of blood. O-Tolidine is often used after a Phenolphthalein blood test to confirm that a suspected stain presumptively may be blood and should be collected for confirmatory testing.
Using our Phenolphthalein and O-Tolidine Presumptive Blood Tests are quick and simple. Each test is administered by first collecting a positive control using the supplied Known Bloodstain Control. Next, a sample of the suspected stain should be collected using either a piece of filter paper or a cotton-tipped swab. One drop of each of the reagents is then applied to the collected sample in the order defined in the directions. The results will be indicated by a specific color change, depending on the reagent used for testing.
Our Phenolphthalein and O-Tolidine Presumptive Blood Test Kit is packaged in a durable, lightweight plastic box for easy and safe transport from one crime scene to another. It includes all the premixed chemicals and supplies required to conduct both the Phenolphthalein and O-Tolidine presumptive blood tests. All of the reagents are supplied in plastic dropper bottles for easy use. The kit also includes Known Bloodstain Controls to ensure that the test results are accurate. All kit components are also available to reorder individually, as needed.
- Plastic Kit Box, 10.5"L x 7" W x 2.25" H
- Phenolphthalein Reagent – 1.5 oz Dropper Bottle
- O-Tolidine Reagent – 1.5 oz Dropper Bottle
- Alcohol Reagent – 1.5 oz Dropper Bottle
- Hydrogen Peroxide Reagent – 1.5 oz Dropper Bottle (2 per kit)
- Distilled Water – 1.5 oz Dropper Bottle (2 per kit)
- Box of Filter Paper
- Box of 3” Cotton-Tipped Swabs
- Known Bloodstain Control (2 per kit)
- Kit Instructions Affixed to Inside of the Box