PMID- 16906221
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20070618
LR  - 20190608
IS  - 1449-1907 (Electronic)
IS  - 1449-1907 (Linking)
VI  - 3
IP  - 4
DP  - 2006 Jul 25
TI  - Low temperature tolerance of human embryonic stem cells.
PG  - 124-9
AB  - This study investigated the effects of exposing human embryonic stem cells (hESC) 
      to 4 degrees C and 25 degrees C 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 25 degrees C and 4 degrees C 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 25 degrees C and 4 degrees C 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 37 degrees C. 
      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.
FAU - Heng, Boon Chin
AU  - Heng BC
AD  - Stem Cell Laboratory, Faculty of Dentistry, National University of Singapore, 5 
      Lower Kent Ridge Road, 119074 Singapore.
FAU - Vinoth, Kumar Jayaseelan
AU  - Vinoth KJ
FAU - Liu, Hua
AU  - Liu H
FAU - Hande, Manoor Prakash
AU  - Hande MP
FAU - Cao, Tong
AU  - Cao T
LA  - eng
PT  - Journal Article
DEP - 20060725
PL  - Australia
TA  - Int J Med Sci
JT  - International journal of medical sciences
JID - 101213954
PMC - PMC1525218
COIS- Conflict of interest: The authors have declared that no conflict of interest 
      exists.
EDAT- 2006/08/15 09:00
MHDA- 2006/08/15 09:01
PMCR- 2006/01/01
CRDT- 2006/08/15 09:00
PHST- 2006/05/25 00:00 [received]
PHST- 2006/07/21 00:00 [accepted]
PHST- 2006/08/15 09:00 [pubmed]
PHST- 2006/08/15 09:01 [medline]
PHST- 2006/08/15 09:00 [entrez]
PHST- 2006/01/01 00:00 [pmc-release]
AID - ijmsv03p0124 [pii]
AID - 10.7150/ijms.3.124 [doi]
PST - epublish
SO  - Int J Med Sci. 2006 Jul 25;3(4):124-9. doi: 10.7150/ijms.3.124.