É.R.A. da Silva1,*, M.H. Martini2 1 Bolsista FUNDAP/Programa de Aprimoramento Profissional em Laboratório de Saúde Pública em Vigilância Sani-

Rats and mice, have accompanied man for many centuries, they adapt to any environment. They are responsible for large losses in world food production and they are important mechanical vectors in transmitting illnesses to man. The presence of hair in food is a characteristic indicator of the infestation by rodents. The presence of hair is related to that of excrements. To recuperate the hairs in food analyses, micro-analytical techniques are used. Rodents have three types of hairs: sensorial hair, fur hair and guard hair. Sensorial hairs are large and thick, having a reduced medulla and nervous tissue in the follicle. Fur hair is fine and weak, small and soft, to maintain the animal’s body temperature, with a medulla composed of a single layer of cells. Guard hair is long and thick and protects the others, it is more pigmented and the medulla has various layers of cells. Fur hair and Guard hair are those most frequently found in food. Between 1995 and 2005, 1,473 microscopic analyses were performed at the Adolfo Lutz