Gene targeting and Calcium handling efficiencies in mouse embryonic stem cell lines

Table 1 Some characteristics of R1 and HM-1 embryonic stem cells and fluorescence activated cell sorting analysis

Cell line	R1	HM-1
Genetic background	(129X1/SvJ x 129S1/Sv) F1 (+/p+tyr-cKitlSl-J/+)1	129/Ola2
Culture conditions	DMEM3 + 15%FBS + 1000 U ESGRO mLIF	DMEM3 + 15%FBS + 1000 U ESGRO mLIF
Cell doubling (in our hands)	14-16 h	12-14 h
Pluripotency
Germline competence4	+	+
In vitro differentiation to form three germ layers5	+	+
Karyotype (FISH)	XY (often XO)	XY more stabile
Euploidy (hoechst staining)	78% ± 4.4%	71% ± 5.3%
Telomerase (PCR)	+	+
FACS analysis (mean ± SE)
Pou5f1 (FACS)	90.6% ± 5.8%	88.8% ± 5.7%
Nanog (FACS)	72.5% ± 6.2%	68.7% ± 2.8%
SSEA-1 (FACS)	58.8% ± 4.1%	65.1% ± 3.1%
Sox2 (FACS)	97.4% ± 1.2%	98.8% ± 0.2%
ALP (enzyme assay)	+	+

¹http://www.mshri.on.ca/nagy;

²HPRT (hypoxanthine phosphoribosyl transferase)-deficient mice derived;

³DMEM media: DMEM (4.5 g/L glucose) + 2 mmol glutamine + 0.1 mmol MEM non-essential amino-acids + 0.1 β-mercaptoethanol + 1 mmol sodium pyruvate + penicillin and streptomycin;

⁴Based on the literature;

⁵Spontaneous and induced (DMSO for cardiac and RA for neuronal) differentiation was tested. PCR: Polymerase chain reaction; FACS: Fluorescence activated cell sorting.