Cell Death

[mks57]

How long does it take for a human, or similar mammal, to completely die after they stop breathing and their heart stops? I'm defining complete death as the death of all cells in the body. According to To Treat the Dead (http://www.msnbc.msn.com/id/18368186) on MSNBC, heart cells still appeared to be alive, more than an hour after "death".

When you are looking at cells under a microscope, how do you know whether they are alive or dead?

[Anaglyph]

How long does it take for a human, or similar mammal, to completely die after they stop breathing and their heart stops? I'm defining complete death as the death of all cells in the body. According to To Treat the Dead (http://www.msnbc.msn.com/id/18368186) on MSNBC, heart cells still appeared to be alive, more than an hour after "death".

How long cells will stay alive depends on many factors: temperature, the level of metabolic activity of the cells, and so on. If kept at ideal 4 degrees Celsius, severed Hands or finger have been replanted successfully after several hours.

Replantation is not recommended when warm ischemia time has exceeded 12 hours for a digit or six hours for a proximal amputation. The digit can survive longer because of the absence of muscle within the part. Cooling of the amputated part can prolong its survival. However, replantation is not recommended when cold ischemic time exceeds 24 hours for a digit amputation or 12 hours for a proximal amputation.cite (http://www.dcmsonline.org/jax-medicine/1998journals/may1998/Replantation.htm)

When you are looking at cells under a microscope, how do you know whether they are alive or dead?

There are several methods to differentiate between living and dead cells by differential staining. Some rely on the ability of living cells to prevent the die from entering the cell, others use the metabolic activity of living cells to produce a color reaction or a fluorescence signal.