A stasis field was a type of technology used to preserve perishable items from decay.
Shortly after assuming command of the USS Farragut following the disastrous mission to Tycho IV in 2257, Lieutenant James T. Kirk ordered all surviving personnel to search for bodies and take them to the cargo bay so that they could be placed in a stasis field, preventing decomposition. (TOS - My Brother's Keeper novel: Constitution)
In 2370, a clutch of Horta eggs was placed in a stasis field on Deep Space 9 to prevent them from hatching while they were still on the station. Unfortunately, Nog and Jake Sisko decided to "borrow" one of the eggs and deactivated the field in the process, leading to the Horta hatching and causing massive damage to the station.
The stasis fields in the Infirmary on Deep Space 9 worked with a golden glow. Also in 2370 the medical stuff of the station placed what they thought was a dead Horta in a stasis field to preserve it's remains. However when his mother came to mourn him and the field was deactivated the Horta awoke, and promptly ate the stasis field generator unit, having in fact only been in a coma. (DS9 novel: Devil in the Sky)