We investigated the effect of Notch signaling, a known regulator of cell fate in numerous developmental systems, on human hematopoietic precursors. We show that activation of endogenous Notch signaling in human CD34(+)CD38(-) cord blood precursors with immobilized Delta-1 in serum-free cultures containing fibronectin and hematopoietic growth factors inhibited myeloid differentiation and induced...

We show a platform that merges a microfluidic chip with lensless imaging for CD4 T-lymphocyte counting at resource-limited settings. To capture CD4 T lymphocytes, anti-CD4 antibody was immobilized on a microfluidic chip. The captured cells were detected by a charge coupled device (CCD) sensor using lensless shadow imaging techniques. Gray scale shadow images of captured cells on the chip (24 mm...

In vivo, growth factors exist both as soluble and as solid-phase molecules, immobilized to cell surfaces and within the extracellular matrix. We used this rationale to develop more biologically relevant approaches to study stem cell behaviors. We engineered stem cell microenvironments using inkjet bioprinting technology to create spatially defined patterns of immobilized growth factors. Using t...

In vivo, growth factors exist as both soluble and as solid-phase molecules, immobilized to cell surfaces and within the extracellular matrix. We employed this rationale to develop more biologically-relevant approaches to study stem cell behaviors. We engineered stem cell microenvironments using inkjet bioprinting technology to create spatially-defined patterns of immobilized growth factors. Usi...

an enzyme electrode was developed using the enzyme sulfite oxidase (ec1.8.3.1) immobilized onto pig intestine. hydrogen peroxide produced was monitored amperometrically. all experimental parameters such as ph, temperature, buffer constituent concentration, were thoroughly investigated and optimized when appropriate. the response to sulfite concentration was linear in the range 5.2´10-6 to 1.02´...

By immunizing mice with killed whole bacterial cells of Brucella abortus S (99), a panel of six hybridomas producing monoclonal antibodies (mAb) specific for the surface antigens of this bacterium were produced. ELISA was used to screen the hybridoma supernatants. Immunoblots of the cell extract indicated that three mAb were specific for S-LPS (Ba-1, Ba-2, Ba-3) and three others were reactive w...

A quantum dot (QD) conjugated whole-cell E. coli biosensor (E. coli–QD bioconjugates) was developed as a new molecular tool for probing cellular damage. The E. coli–QD bioconjugates were viable and exhibited fluorescence emission at 585 nm. Scanning electron microscopy (SEM) analysis of E. coli–QD bioconjugates revealed that the QDs were immobilized on the cell-surfaces and the fluorescence emi...