The visit to the government lab near Kuala Lumpur came after a chemist last week testified there were traces of nerve agent VX on the women's clothes.
Raja Subramaniam's testimony was the first evidence directly linking the women to the poison used to kill Kim Jong-Nam as he waited at a crowded airport near the capital.
Indonesian Siti Aisyah and Vietnamese Doan Thi Huong, in their 20s, are accused of smearing VX on Kim's face in February in a hit that stunned the world.
Related reading
Kim Jong-un promotes sister, reaffirms nuclear drive
The women, who were arrested a few days after the killing and face death by hanging if convicted, have pleaded not guilty to murdering the estranged half-brother of Kim Jong-Un as he waited to board a flight to Macau.
The defendants say they were duped into believing they were taking part in a prank for a reality TV show, and their lawyers blame North Korean agents for the assassination.
On Monday the judge, prosecutors and defence lawyers headed to the laboratory along with Raja.
A member of Aisyah's legal team put on a lab coat, mask and gloves and entered a room to examine clothes, nail clippings and blood samples, said Aisyah's lawyer Gooi Soon Seng.
"The whole process was to identify the exhibits," Gooi said.
But he added that a blazer said in court to have been worn by Kim Jong-Nam and to be contaminated with VX was not shown to them.
The trial was supposed to move back to Shah Alam High Court, near the capital, and resume in the afternoon. But it was postponed until Tuesday after Raja, who was due to be questioned by the defence, complained of feeling tired.
The murder sparked a fierce row between Malaysia and North Korea, which is suspected of ordering the hit. Pyongyang denies the allegation.
