His body is to undergo tests to find out whether his death in Paris in 2004 was caused by poisoning.
Arafat’s medical records say he had a stroke resulting from a blood disorder.
But France began a murder inquiry in August after Swiss experts hired by a documentary crew found radioactive polonium-210 on Arafat’s personal effects.
His tomb, in Ramallah in the West Bank, was sealed off earlier this month.
Once the body is removed from the tomb inside the stone-clad tomb mausoleum, scientists from France, Switzerland and Russia will each take samples, former Palestinian intelligence chief Tawfik Tirawi told reporters.
Each team will conduct its own independent analysis of the sample, he said, and then body will be reburied the same day with military honours.
Arafat, who led the Palestine Liberation Organisation for 35 years and became the first president of the Palestinian Authority in 1996, fell violently ill in October 2004 at his compound.
Two weeks later he was flown to a French military hospital in Paris, where he died on 11 November 2004, aged 75.
His widow, Suha, objected to a post-mortem examination at the time, but later appealed to the Palestinian Authority to permit the exhumation “to reveal the truth”.
Many Palestinians continue to believe that Israel poisoned him. Israel has denied any involvement. Others allege that he had Aids.
In 2005, the New York Times obtained a copy of Arafat’s medical records, which it said showed he died of a massive haemorrhagic stroke that resulted from a bleeding disorder caused by an unknown infection.
Independent experts who reviewed the records told the paper that it was highly unlikely that he had died of Aids or had been poisoned.
A murder inquiry was launched by French prosecutors in August after an investigation by Al Jazeera TV, working with scientists at the Institute of Radiation Physics (IRA) at the University of Lausanne in Switzerland, found “significant” traces of polonium-210 present in samples taken from Arafat’s personal effects, including his trademark keffiyeh headdress.
In some cases, the elevated levels were 10 times higher than those on control subjects, and most of the polonium could not have come from natural sources, the scientists said.