Arafat became suddenly ill in 2004, and died a month later reportedly of a stroke. However, the immediate cause is now being questioned eight years after his mysterious death.
Earlier this year, radioactive isotope polonium was discovered on clothes said to be his, fueling speculation that he may have been poisoned.
Many Israelis held Arafat responsible for the bloody Palestinian uprising of the early 2000s leading many Arabs to place the culpability on Israel.
Tests launched by Palestinians earlier this year were inconclusive. Experts from Switzerland, France and Russia will examine the samples.
The Palestinian investigative team says the results will take at least three months.
The Associated Press contributed to this report.