Question: How were tissue samples from the last "bucardo" preserved
About the article "Cloning", section "Cloning extinct and endangered species".

Candidate passages:
 extinct and endangered species.
Cloning, or more precisely, the reconstruction of functional DNA from extinct species has, for decades, been a dream of some scientists.
Current cloning techniques have an average success rate of less than 5 percent, even when working with familiar species; cloning wild animals is usually less than 1 percent successful.
The possible implications of this were dramatized in the best-selling novel by Michael Crichton and high budget Hollywood thriller "Jurassic Park".
Early hopes to save species through cloning have been dashed as the difficulties of cloning any species have made progress very slow.
Several tissue banks have come into existence, including the "Frozen Zoo" at the San Diego Zoo, to store frozen tissue from the world's rarest and most endangered species.
In 2001, a cow named Bessie gave birth to a cloned Asian gaur, an endangered species, but the calf died after two days.
In 2003, a banteng was successfully cloned, followed by three African wildcats from a thawed frozen embryo.
These successes provided hope that similar techniques (using surrogate mothers of another species) might be used to clone extinct species.
Anticipating this possibility, tissue samples from the last "bucardo" (Pyrenean Ibex) were frozen in liquid nitrogen immediately after it died in 2000.
Researchers are also considering cloning endangered species such as the giant panda and cheetah.
In 2002, geneticists at the Australian Museum announced that they had replicated DNA of the Thylacine (Tasmanian Tiger), at the time extinct for about 65 years, using polymerase chain reaction.
However, on February 15, 2005 the museum announced that it was stopping the project after tests showed the specimens' DNA had been too badly degraded by the (ethanol) preservative.
On 15 May 2005 it was announced that the Thylacine project would be revived, with new participation from researchers in New South Wales and Victoria.
In January 2009, for the first time, an extinct animal, the Pyrenean ibex mentioned above was cloned, at the Centre of Food Technology and Research of Aragon, using the preserved DNA of the skin samples from 2001 and domestic goat egg-cells.
The ibex died shortly after birth due to physical defects in its lungs.
One of the most anticipated targets for cloning was once the Woolly Mammoth, but attempts to extract DNA from frozen mammoths have been unsuccessful, though a joint Russo-Japanese team is currently working toward this goal.
In January 2011, it was reported by Yomiuri Shimbun that a team of scientists headed by Akira Iritani of Kyoto University had built upon research by Dr. Wakayama, saying that they will extract DNA from a mammoth carcass that had been preserved in a Russian laboratory and insert it into the egg cells of an African elephant in hopes of producing a mammoth embryo.
The researchers said they hoped to produce a baby mammoth within six years.
Scientists at the University of Newcastle and University of New South Wales announced in March 2013 that the very recently extinct gastric-brooding frog would be the subject of a cloning attempt to resurrect the species.
Plenty of phosphate is required, either from seawater or from the tissues of the decaying organism.
In some cases microbes control the phosphatization, and the remains of the microbes that were "feeding" on the preserved tissue form the fossil.
In other, the tissue itself is the source of phosphate and its phosphatized remains form the fossil.
In the intermediate case the phosphatized tissue retains the impressions of the phosphatizing microbes. 
Later investigations.
In 1984, when HIV was first discovered (originally called HTLV-3), and was spreading rapidly in the homosexual male communities of New York City and Los Angeles, Dr. Marlys Witte, one of the doctors who, like Elvin-Lewis, had cared for Rayford before death and also assisted in the autopsy, thawed and tested preserved tissue samples from Rayford's autopsy, which tested negative.
Three years later, in June 1987, Witte decided to test the tissue samples again using Western blot, the most sensitive test then available.
The Western blot test found that antibodies against all nine detectable HIV proteins were present in Rayford's blood.
A second test found identical results. 
Most tumor banks collect their tumor samples from discarded tissues not needed for pathologic diagnosis, after patients undergo surgery to remove the tumor.
The tissue is often snap frozen in liquid nitrogen but may also be preserved in special fixative such as RNAlater (which preserves RNA), or formalin which preserved tissue architecture.
Many Cancer Centers in the U.S. have a Tumor Bank to supply biomedical scientists with actual patient samples of cancer and associated adjacent normal tissue.
This process is currently a high priority to support more Translational Research. 
The official investigation that followed ruled that Hall had died from apoplexy.
However, in 1968, Hall's biographer Chauncey C. Loomis, a professor at Dartmouth College, made an expedition to Greenland to exhume Hall's body.
Because of the permafrost, Hall's body, flag shroud, clothing and coffin were remarkably well preserved.
Tests on tissue samples of bone, fingernails and hair showed that Hall died of poisoning from large doses of arsenic in the last two weeks of his life.
This diagnosis is consistent with the symptoms party members reported.
It is possible that Hall dosed himself with the poison, as arsenic was a common ingredient of quack medicines of the time.
But it is considered possible that he was murdered by one of the other members of the expedition, possibly Dr. Bessels.
No charges were ever filed.