In their search for the source of stem cells, scientists discovered an unusual source.  The baby teeth or temporary teeth that children lose at approximately 6 years old contain a rich supply of stem cells in the dental pulp as studied using fluorescent microscopy.  The accidental discovery could have significant implications since the stem cells remain alive inside the tooth for a short after it falls out of the mouth of a child as noted through fluorescent microscopy.  This suggests that the cells could be readily available for research.
Comparing the stem cells taken from the temporary teeth to the adult stem cells in the body through fluorescent microscopy showed that the stem cells from the baby teeth can last longer, grow fast in culture and have a strong potential to stimulate the formation of specialized dentin, bone and neuronal cells.  The scientists consider that they may have identified an important and readily accessible source of stem cells.  These stem cells might be manipulated to treat damaged teeth, as well as stimulate the regeneration of the bone and treat neural injury or disease.
For years, doctors have harvested stem cells successfully from umbilical cords. The stem cells harvested have been closely examined using fluorescent microscopy. Scientists believe that the stem cells in the tooth are probably dormant remnants of an early developmental process.
Shi and his associates named the cells as SHED.  SHED stands for Stem Cells for Human Exfoliated deciduous teeth.  The term deciduous teeth is the formal name for baby teeth.  Children usually develop a set of 20 deciduous teeth that appear after six month of life and are generally replaced. The unique acronym SHED differentiates the SHED stem cells from adult tissues like in bone or brain.
Although stem cells research is popular during the past years, still people refer to it in general terms of post natal and adult stem cells as though they are one and the same.  What differentiates post natal cells from children from adult stem cells when viewed using fluorescent microscopy is that postnatal cells from children may act differently than adult stem cells.
What actually triggered Shi’s interest in the study of stem cells was when his daughter, Julia asked for assistance in pulling out a loose baby tooth.  From the pulled tooth, there was some colored tissue inside the tooth.  When examined through fluorescent microscopy in the laboratory it had beautiful pulp tissue left over inside the tooth.
The tooth was placed into a liquid medium which is used to culture cells and studied through fluorescent microscopy. Thereafter, the living stem cell from the tissue was successfully isolated and monitored with fluorescent microscopy.  This discovery leads the way to the collection of more exfoliated teeth for further study.
The group of scientists initiated an initial round of studies which hope to determine whether the cells would grow well in   culture.  With the dental pulp extracted from the children’s exfoliated incisors, they discovered that more or less 12 to 20 stem cells from each tooth have the capability to colonize and grow in culture as observed through fluorescent microscopy.
Another interesting fact is that SHED acted differently than dental pulp stem cells from permanent teeth as observed using fluorescent microscopy.  They showed the capacity to grow quickly as well as double their populations in culture at a greater rate.  Follow up experiments were conducted to determine whether SHED also possessed the potential to switch neural and fat cells.  Under specific cell culture conditions, the cells reacted accordingly as observed through fluorescent microscopy expressing a variety of proteins indicative of neural and fat cells.