 During cross examination he testified that during preparation for PCR testing that a reference card is created using Simpson's donated blood for comparison to the evidence items.When asked, he initially stated he was not sure he changed his gloves when he moved from the reference card to the evidence items but then remembered he did change his gloves.In either case, he maintains that he never touched any of the evidence items with his gloved hands and used sterile instruments to handle the items that were then changed between each item.