A Los Angeles County Superior Court judge made the ruling Wednesday.
The judge left it up to the defense to decide whether the coroner's office or a private lab should perform the tests.
A preliminary hearing is set to begin Tuesday to determine whether there is enough evidence for Conrad Murray, 57, to stand trial on an involuntary manslaughter charge.
He has pleaded not guilty.
The prosecution suggests the defense will claim Jackson killed himself by injecting more of the anesthetic propofol than Murray administered.