In medicine, the term transplantation may refer to the specific process of transferring cells or organs between a donor and recipient (i.e., the transplant), or the entire process of donor-recipient matching, surgical or other transfer, and medical management of the recipient.
Some organs or tissue may be harvested from a living donor. Perhaps the most common transplant, although not always realized as such, is blood. For organs, such as the heart, which cannot be transplanted from a living donor, ethical issues become complex. Some legal jurisdictions assume that competent persons must explicitly declare their willingness to be donors, while others assume that those unwilling to be donors will "opt out".
Ethics of donation
The first step is determining brain death, has usually been considered the requisite. Nevertheless, arguments are made for the possibly ethical practice of "non-beating heart donation", when there is cardiac arrest, and a presumption of an irreversible state leading to brain death. 
Recipient selection: ethical issues
Recipient selection: tissue matching
- Michael Potts (2007), "Commentary: Truthfulness in transplantation: non-heart-beating organ donation", Philosophy, Ethics, and Humanities in Medicine 2: 17, DOI:10.1186/1747-5341-2-17