Forensic Examination Of Hair Samples Biology Lab Report Template (Page 3 of 3) in pdf

Hair shape (round or oval cross-section) and texture (curly or straight) is influenced heavily by

genes. However, nutritional status and intentional alteration (heat curling, "perms") can affect

the physical appearance of hair.

III. Procedure

A. Hair – Use prepared slides of hair samples from different species provided by your teacher.

1. Observe prepared slides from six different species of animals. Make a sketch and list

the characteristics of each hair observed. Include in your observations hair color,

medulla type, medullary index and any other specific observations you make. Record

this information in the data chart provided.

2. Observe four different prepared slides of human hair. Make a sketch and list the

characteristics of each hair observed. Include in your observations hair color, medulla

type, medullary index and any other specific observations you make. Record this

information in the data chart provided.

3. Obtain three samples of unknown hair. Record the sample number of the unknown.

Prepare a wet mount slide of each hair. Make a sketch and list the characteristics of

each hair observed. Include in your observations hair color, medulla type, medullary

index and any other specific observations you make. Record this information in the

data chart provided.

B. Preparation and Examination of Cuticle Scale Casts

1. Obtain three microscope slides. Coat one slide with a thin layer of clear nail polish. Let

the polish stand for 45 – 60 sec until it begins to set. It is important that you do not

allow the polish to harden too much because then the hair will not make an impression.

This takes practice, and you may have to try a few times before getting a usable

impression.

2. Carefully embed a single hair from one of the unknowns into the partially set nail polish.

Once the hair in the polish is dry, peel the hair off.

3. Repeat the process for the other two unknowns.

4. Observe the hair scale impressions left behind under low power and high power.

5. Identify the cuticle pattern type on each of your prepared slides.

C. Identification of Unknown Hairs

1. Identify each of your unknown hair samples and explain why you made that

identification. Your explanation should include specific observations you made and how

they relate to known characteristics of particular human or animal hairs. Be thorough!

L_05x01_Hair

Forensic Examination Of Hair Samples Biology Lab Report Template Page 3