Low temperature tolerance of human embryonic stem cells

Boon Chin Heng1, Kumar Jayaseelan Vinoth1, Hua Liu1, Manoor Prakash Hande2, Tong Cao1

1. Stem Cell Laboratory, Faculty of Dentistry, National University of Singapore, 5 Lower Kent Ridge Road, 119074 Singapore.
2. Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, MD9, 2 Medical Drive, 117597 Singapore.

Int J Med Sci 2006 3:124-129 http://www.medsci.org/v03p0124

Abstract

This study investigated the effects of exposing human embryonic stem cells (hESC) to 4oC and 25oC for extended durations of 24h and 48h respectively. Cell survivability after low temperature exposure was assessed through the MTT assay. The results showed that hESC survivability after exposure to 25oC and 4oC for 24h was 77.3 ± 4.8 % and 64.4 ± 4.4 % respectively (significantly different, P < 0.05). The corresponding survival rates after 48h exposure to 25oC and 4oC was 71.0 ± 0.5 % and 69.0 ± 2.3 % respectively (not significantly different, P > 0.05). Spontaneous differentiation of hESC after low temperature exposure was assessed by morphological observations under bright-field and phase-contrast microscopy, and by immunocytochemical staining for the pluripotency markers SSEA-3 and TRA-1-81. hESC colonies were assigned into 3 grades according to their degree of spontaneous differentiation: (1) Grade A which was completely or mostly undifferentiated, (2) Grade B which was partially differentiated, and (3) Grade C which was mostly differentiated. In all low temperature exposed groups, about 95% of colonies remain undifferentiated (Grade A), which was not significantly different (P > 0.05) from the unexposed control group maintained at 37oC. Additionally, normal karyotype was maintained in all low temperature-exposed groups, as assessed by fluorescence in situ hybridization (FISH) of metaphase spreads with telomere and centromere-specific PNA probes. Further analysis with m-FISH showed that chromosomal translocations were absent in all experimental groups. Hence, hESC possess relatively high-tolerance to extended durations of low temperature exposure, which could have useful implications for the salvage of hESC culture during infrequent occurrences of incubator break-down and power failure.

Keywords: human embryonic, stem cells, low temperature

Thank you for your effort in starting a thread on this subject, but I think it would make more sense to add your thoughts on a subject rather than cutting and pasting a data from an article.

In other forums there is generally a rule against just posting web link or some other information that has been copied. Mods: please feel free to correct me if you disagree.

I agree - you can DISCUSS any pertinent question in the forum - and low temperature tolerance and survival of cells qualifies just fine. However, copying and pasting an abstract is not good practice- even with an open access journal.