C - DTU Nanotech - Danmarks Tekniske Universitet

Abstract
In this thesis the feasibility to use Peltier cooling for freezing small samples and the combi-
nation of this sampling system with a reactor chamber to compose a bio–microreactor setup
is presented.
In the first part of this thesis, four different sampling vessels are tested with respect to the
efficiency of Peltier elements. It is shown that a sampling device with a laser machined
bottom provides the best freezing times. With this device several other studies related to
the freezing times of PBS–buffer, LB–medium and Escherichia coli cells are investigated.
For the E. coli cells also the viability after freezing and thawing is tested. The data show
that the freezing of samples can be conducted with a Peltier element.
In the second part, a bio–microreactor is developed, in which the improved sampling device
from the first part is integrated. Besides the sampling device the bio–microreactor consists
of a reactor chamber in which the temperature is maintained with a heat wire device. The
reactor chamber is connected through a PVC–tube interconnection and a teflon tube to the
sampling chamber. The setup is tested with PBS–buffer.
The data demonstrate that Peltier cooling for freezing samples and the combination with a
reactor chamber to compose a bio–microreactor setup is suitable.