Laser-assisted generation of human induced pluripotent stem cells.

This unit describes a procedure for generating human induced pluripotent stem cells (hiPSCs) using the Laser-Enabled Analysis and Processing (LEAP®) system, which combines high-throughput cell imaging with laser-mediated cell manipulation. Use of this system should not only improve the quality and uniformity of hiPSCs produced, but ultimately enable a more rapid, efficient, high-throughput, and automated production process.

Laser-Based Propagation of Human iPS and ES Cells Generates Reproducible Cultures with Enhanced Differentiation Potential.

Proper maintenance of stem cells is essential for successful utilization of ESCs/iPSCs as tools in developmental and drug discovery studies and in regenerative medicine. Standardization is critical for all future applications of stem cells and necessary to fully understand their potential. This study reports a novel approach for the efficient, consistent expansion of human ESCs and iPSCs using laser sectioning, instead of mechanical devices or enzymes, to divide cultures into defined size clumps for propagation.

High-Resolution Genomic Profiling of Chromosomal Abnormalities in Human Stem Cells Using the 135 K StemArray.

Culturing stem cells for an extended period of time can lead to acquired chromosomal aberrations. Determining the copy number variant (CNV) profile of stem cell lines is critical since CNVs can have dramatic effects on gene expression and tumorigenic potential. Here, we describe an improved version of our StemArray, a stem-cell-focused comparative genomic hybridization (aCGH) microarray, which contains 135,000 probes and covers over 270 stem cell and cancer related genes at the exon level.

Array-comparative genomic hybridization characterization of human pluripotent stem cells.

During culture adaptation, human embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) tend to acquire chromosomal aberrations. Generally, stem cell lines are screened for large-scale chromosomal changes using low resolution karyotype analysis. Recent studies characterizing human stem cells using array-comparative genomic hybridization (aCGH) suggests most abnormalities acquired during culture are under the resolution of karyotype analysis and therefore are routinely missed.

High resolution array-CGH characterization of human stem cells using a stem cell focused microarray.

Human embryonic and induced pluripotent stem cells (ESCs, iPSCs) that are cultured for an extended period of time are susceptible to genomic instability. Chromosomal aberrations decrease the reliability and reproducibility of experiments and could deem the cells unusable for therapeutic purposes. The genetic stability of human ESCs and iPSCs is commonly monitored by karyotype analysis.