Microfluidic assessment of functional culture-derived platelets in human thrombi under flow.

Despite their clinical significance, human platelets are not amenable to genetic manipulation, thus forcing a reliance on mouse models. Culture-derived platelets (CDPs) from human peripheral blood CD34(+) cells can be genetically altered and may eventually be used for transfusions. By use of microfluidics, the time-dependent incorporation of CD41(+)CD42(+) CDPs into clots was measured using only 54,000 CDPs doped into 27 μL of human whole blood perfused over collagen at a wall shear rate of 100 sec(-1).

MicroRNA screen of human embryonic stem cell differentiation reveals miR-105 as an enhancer of megakaryopoiesis from adult CD34+ cells.

MicroRNAs (miRNAs) can control stem cell differentiation by targeting mRNAs. Using 96-well plate electroporation, we screened 466 human miRNA mimics by four-color flow cytometry to explore differentiation of common myeloid progenitors (CMP) derived from human embryonic stem cells (hESCs). The transfected cells were then cultured in a cytokine cocktail that supported multiple hematopoietic lineages.

An enhanced approach for engineering thermally stable proteins using yeast display.

Many biotechnology applications require the evolution of enhanced protein stability. Using polymerase chain reaction-based recovery of engineered clones during the screen enrichment phase, we describe a yeast display method capable of yielding engineered proteins having thermal stability that substantially exceeds the viability threshold of the yeast host. To this end, yeast-enhanced green fluorescent protein destabilized by dual-loop insertion was engineered to possess a substantially enhanced resistance to thermal denaturation at 70°C.