Assistant Laboratory Animal Technician (ALAT) Practice Exam 2026 – Complete All-in-One Guide to Exam Success!

The reddish material found in the tears and saliva of rats is called porphyrin. Porphyrins are a group of organic compounds, and in the context of rats, the presence of porphyrin in bodily fluids is often related to the breakdown of hemoglobin. The reddish coloration is due to the porphyrin molecule's ability to interact with light, leading to a distinct pigment.

This phenomenon is particularly notable in certain species of rodents, including rats, where porphyrin can be secreted in response to stress, illness, or other factors. It serves as a unique diagnostic indicator that can alert handlers to potential health issues in the animal. The understanding of porphyrin's role and significance in laboratory animals contributes to better veterinary care and husbandry practices.

In contrast, hemoglobin is a protein responsible for oxygen transport in blood, myoglobin functions similarly in muscle tissue, and melanin is the pigment responsible for coloration in skin, hair, and eyes. These substances do not share the same association with the specific reddish material produced in the tears and saliva of rats.