Lack of Population Diversity in Commonly Used Human Embryonic Stem-Cell Lines

The Authors Reply: Focosi points out several appropriate alternatives to the methods depicted in our video of bone marrow aspiration and biopsy.Our experience does not suggest that the degree of pain associated with the procedure is lower when the biopsy is performed first, and the sequence probably does not matter in the sedated patient.We agree that a frail biopsy specimen may be damaged by collection onto gauze; however, immediate inspection of the biopsy specimen is critical and requires placement onto gauze or a glass slide.It is not uncommon for an extracted biopsy specimen to contain exclusively cortical bone without marrow, which is an inadequate sample for evaluation.Immediate placement into formalin precludes the ability to inspect the specimen appropriately.In addition, a touch preparation may provide useful information.Although collecting aspirate into anticoagulated vacuum tubes may be feasible, in certain conditions, marrow can be difficult to aspirate and requires substantial suction.There is no ability to modify the force or pull when using vacuum tubes.In regard to the preparation of slides, we agree that a slide should be appropriately anchored to create an evaluable aspirate smear.