BUCHI Encapsulator B-390 - Manual (Page 43)

6 Operation
43 B-390 Operation Manual, Version C
Table 6-4: Optimal working conditions for the Encapsulator determined with alginate solution
Nozzle diameter [ µm] Flow rate * [mL/min] Frequency interval ** Amplitude Air pressure [bar]
1.0 mm 30 to 40 40 to 220 Hz 2 to 6 0.3 to 0.6
750 µm 19 to 25 40 to 300 Hz 2 to 5 0.3 to 0.5
450 µm 9 to 14 150 to 450 Hz 2 to 5 0.3 to 0.5
300 µm 5.5 to 7 400 to 800 Hz 1 to 3 0.3 to 0.5
200 µm 3.5 to 4.5 600 to 1200 Hz 1 to 3 0.4 to 0.6
150 µm 2.3 to 2.8 800 to 1800 Hz 1 to 3 0.4 to 0.6
120 µm 1.5 to 1.8 1000 to 2500 Hz 1 to 4 0.5 to 0.7
80 µm 1.1 to 1.3 1300 to 3000 Hz 1 to 4 0.5 to 0.7
* Tested with 2 % low viscosity grade alginate solution for 750 µm and 1.0 mm nozzle, with 1.5 %
alginate solution for the 150 to 500 µm nozzle and with 1.2 % alginate solution for the 80 and 120 µm
nozzles.
**Upper values with application of high voltage.
NOTE
For solutions with a viscosity different from the tested one, it can be said that:
• the higher the viscosity the higher the minimal jet velocity
• the higher the viscosity the higher the working flow rate
• the higher the viscosity the lower the optimal frequency
• the higher the viscosity the larger the beads
6 .7 .1 Bead productivity and cell density
Figures 6-6 and 6-7 indicate the amount of beads formed from 1 mL of liquid. About 30,000 beads
with a diameter of 0.4 mm will be formed, but only 2,000 with a diameter of 1 mm.
Figures 6-8 and 6-9 indicate the number of cells which are encapsulated in one bead for a given
cell density and bead diameter. These figures may help you select the appropriate cell density in the
immobilization mixture. For example, if the immobilization mixture contains 1×10
6 cells per mL, then
about 33 cells are, on average, in each 0.4 mm bead, but, about 520 cells will be in each 1 mm bead.