Blood Lab #1 is it Blood?

  Prelab Notes:

  Purpose: To identify an unidentified stain as blood using the Kastle-Meyers Test . Identify bloodstains using Luminol Reactions.

Part I: Peroxidase Test:

Procedure:

1.    Copy the data table into your notebook.

2.    Cut a small square piece (1 cm x 1cm) of the suspect stain and material. Place the material into a well of the glass plates using tweezers. Do not touch with your fingers.

3.    Add 3 drops of Phenolphthalein Reagent (record result) and then 3 drops Hydrogen Peroxide (3%) Solution to the material. Record results. A positive result for blood is a pink color and some foaming. A negative result would be no pink color or foaming.

4.    Keep all SWATCHES of material; label them on the Swatch form. DO NOT THROW AWAY!!! YOU WILL NEED THEM FOR PART II.

5.    Repeat the procedures for all of the suspect stain.

6.    UNKNOWN: dampen a q-tip with distilled water. Rub the q-tip on a suspected stain in the room. Place the Q-tip in one of the wells. Repeat steps

Part 2: Luminol Test

COPY Data table into your notebook

1.    Using the Luminol misting bottle, spray the swatches with a light mist.

2.    Turn off all lights and darken the room.

3.    Run the UV light over the Swatch Form and record the result for each swatch in the data table.

  Conclusion Questions: Answer in your Science Notebook:

1.    Did you get any FALSE –positive reactions for blood in Part I, in other words did you get a positive for blood with a substance  that is NOT blood? EXPLAIN How this possible?

2.    Do these tests identify the blood as human? Explain your answer.

3. Can you PRESUME your unknown stain blood? Explain.