 Hair is a filamentous biomaterial that grows from follicles found in the dermis.  Found exclusively in mammals, hair is one of the defining characteristics of mammalian class.  Hair have a structure consisting of several layers:- a)Cuticle b)Cortex c)Medulla Introduction of Hair

 Cuticle is outer layer of the hair shaft.  It consist of several layers of flat, thin cells without over-lapping one another. Cuticle

Cortex  The region of a hair located between cuticle & medulla layer containing pigment granules known as Cortex.

Medulla  It is the central part of the hair, made up of large loosely connected cells which contain Keratin.  Sometimes medulla may be absent in some species.  On the basis of appearance of medulla it is divided into five types:- 1)Continuous 2)Interrupted 3)Fragmented 4)Solid 5)Absent

Human Hair :- Different Sites Scalp Pubic Vulvar Chest Beard Axiliary Eyebrow Eyelash Nose Limb Buttocks

FeatureHuman HairAnimal Hair CortexThe width of cortex greater than medulla Usually less than width of medulla Distribution of pigmentTowards cuticleCentral or denser towards medulla MedullaMedulla dis-continuousMedulla continuous ScalesImbricateCoronal, ring form Differences between Human & Animal Hair

Sampling Of Hair  Spread the exhibit on a clean white surface under proper illumination.  With hand magnifier, carefully locate any loose hair and collect.  Hair can be collected by forceps or transferred to adhesive tape.  Samples collected should be packed in cellophane or paper folders with proper labeling on them.  Root bulb and follicle of hair should be carefully preserved for determination of sex, serological and DNA Examination.

Examination Of Hair Temporary Mount Scale Casting Cellulose Acetate Method Polaroid Coater Method Permanent Mount Cross Sectioning Micrometry

Temporary Mount  Make a temporary mount of the hair sample on a clean slide with the distilled Water or glycerin. Cover with cover slip.  Observe morphological characteristics under microscope.

 On a clean microscopic slide, place a thin layer of cellulose acetate paste with low viscosity.  With fine forceps, place hair on to the cellulose acetate paste and press with another clean slide.  Allow it to dry for 2-5 min.  Observe scales of hair under microscope.

 Place the hair on a clean microscope slide, securing the ends with cellophane tape.  Using a Polaroid film coater, make 2 or 3 passes along the length of the hair.  Allow the coating to dry for 23 hours.  After removing the cellophane tape, gently peel the hair from the slide.  With a sharp scalpel, slice away the excess coating protruding above the flat surface of the scale cast.  Observe the scale impressions microscopically.

Permanent Mount  Place hair on slide in a drop of xylene and add permanent mounting medium.  Place a cover slip on the hair allowing the medium.  Label the slide appropriately and allow it to dry for 48 hours.

Cross Sectioning  Clean hair in solution of ether and ethanol in ratio 1:1  Bundle the samples and dip in a block of molten wax and allow to cool.  Cross sections can be taken either with a sharp blade or with a microtone to a thickness of 5-10 microns.  Place sections on a clean slide and dissolve wax with a drop of xylene.  Prepare permanent mount of the sections and examine under the microscope.

Micrometry With the help of micrometer measure following distances & calculate different indices:  Maximum diameter of the shaft.  Number of scales per unit length.  Diameter of hair in microns / scale count.  Maximum diameter of hair medulla / Maximum diameter of hair shaft.  Minimum diameter of shaft / Maximum diameter of the shaft x 100

Report Writing Species of Origin On the basis of morphological examination Sex On the basis of microscopic examination Site On the basis of morphological examination Comparison On the basis of morphological examination