Beads as Carriers for Cellular Assays
3.6.4.
Culturing mammalian cells on beads is a well established technique, routinely used in industry, for production of growth hormone and other pharmaceuticals. In a laboratory scale , it is a routine to work with cell cultures grown on suspended beads in a 10mL culture tube. The culturing procedure results in a suspension where all beads are covered uniformly with a cell culture that has the same properties (degree of confluence, cell cycle distribution, viability and cell line passages). By sampling about 10,000 beads of Cytodex into a flow cell, there are about 50,000 cells selected for an experiment.
The key and unique advantage of BI-based cellular assays is that beads – and cells are retrieved from one culture tube that yields several hundred cellular samples with identical properties since the cells are randomly distributed on the bead surfaces.
Therefore:
- there is no biological variability within the series of experiments, carried out in a
reasonably short period of time.
- there is no hysteresis (memory effect) caused by stimulants, applied in previous
experiments, since fresh cell culture can be used as needed by renewing the
bead column.
- stimulants of known potency can be used as calibrants by bracketing a series of
unknown investigated stimulants.
- a large number of cells can be monitored by UV-VIS and fluorescence spectroscopy
as well as by voltammetry.
- the number of cells adherent to Cytodex beads can be automatically counted.
