On 2015 Nov 26, Deepa Bhartiya commented:

This group’s inability of detect VSELs in mouse bone marrow is indeed surprising. They could not detect VSELs in bone marrow (0.002% events in the size range of 2-4 microns appeared debris). Bone derived VSELs were greater than 6 microns in size and did not express pluripotent markers. A careful look at their protocols shows that all processing was done at 1500 rpm. We know from our experience that VSELs pellet down at 3000 rpm and this could be one of the reasons for their negative results. We have detected 0.022+0.002% cells as VSELs in mouse BM which express pluripotent markers by immuno-localization and confocal microscopy as well as by qRT-PCR. We have earlier reported that when cord blood is subjected to density gradient centrifugation, VSELs are invariably discarded along with the red blood cells. Apparently this group needs to revise their protocols to isolate VSELs. We have discussed this point in details in our recent paper also(http://www.ncbi.nlm.nih.gov/pubmed/25976079). Furthermore, presence of VSELs in few numbers should not be an issue of concern for regenerative medicine. In contrast to pluripotent ES/iPS cells which exist only in a Petri dish, VSELs are endogenous pluripotent stem cells present in adult tissues. We need to understand and learn how to manipulate them in the body. VSELs will self-renew themselves and give rise to committed cells which in turn are expected to divide rapidly and undergo clonal expansion into large numbers of tissue committed progenitors.

On 2015 Nov 26, Deepa Bhartiya commented:

This group’s inability of detect VSELs in mouse bone marrow is indeed surprising. They could not detect VSELs in bone marrow (0.002% events in the size range of 2-4 microns appeared debris). Bone derived VSELs were greater than 6 microns in size and did not express pluripotent markers. A careful look at their protocols shows that all processing was done at 1500 rpm. We know from our experience that VSELs pellet down at 3000 rpm and this could be one of the reasons for their negative results. We have detected 0.022+0.002% cells as VSELs in mouse BM which express pluripotent markers by immuno-localization and confocal microscopy as well as by qRT-PCR. We have earlier reported that when cord blood is subjected to density gradient centrifugation, VSELs are invariably discarded along with the red blood cells. Apparently this group needs to revise their protocols to isolate VSELs. We have discussed this point in details in our recent paper also(http://www.ncbi.nlm.nih.gov/pubmed/25976079). Furthermore, presence of VSELs in few numbers should not be an issue of concern for regenerative medicine. In contrast to pluripotent ES/iPS cells which exist only in a Petri dish, VSELs are endogenous pluripotent stem cells present in adult tissues. We need to understand and learn how to manipulate them in the body. VSELs will self-renew themselves and give rise to committed cells which in turn are expected to divide rapidly and undergo clonal expansion into large numbers of tissue committed progenitors.