Team:ETH Zurich/lab/bead
From 2014.igem.org
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The beads are better visible in liquid when light shines from the side. So it is easier to load the [https://2014.igem.org/Team:ETH_Zurich/lab/chip the chip] with help of a cell phone light. An inoculation loop with a diameter of around 2 mm can be used to conveniently transfer the beads. | The beads are better visible in liquid when light shines from the side. So it is easier to load the [https://2014.igem.org/Team:ETH_Zurich/lab/chip the chip] with help of a cell phone light. An inoculation loop with a diameter of around 2 mm can be used to conveniently transfer the beads. | ||
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Revision as of 20:47, 15 October 2014
Beads
Overview
Properties
Na2+ alginate is a viscous liquid, however, upon addition multivalent ions such as Ca2+ cross-linking of the polysaccharides occurs. Thus gelling of alginate can be achieved by the addition of a Ca2+. For encapsulation the cells or macromolecules are added to Na2+ alginate and subsequently immobilized during the gelling process. In fact, the encapsulation process is mild and compatible with most living cells. The high porosity of the ionically cross-linked polysaccharide lattice allows diffusion of nutrients and other substances into and out of the bead. This property of Ca2+ alginate allows cultivation of bacteria inside beads and does not prevent communication via small molecules between colonies of different beads. Substances such as phosphate or EDTA are sequestrating Ca2+ and thus destabilizing the alginate gel[25]. This fact should be considered when choosing the cultivation medium.
Production
Loading the Chip