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Section 4: FAQ
Q1: What are the characteristics of the silicone chamber?
A1:
The strain chamber is made from silicone elastomer consisting of
polydiethylsiloxane as its major component. The chamber surface is strongly
hydrophobic and cells have difficulty attaching to it; therefore, the chamber surface
should be coated with an extra-cellular matrix like fibronectin, collagen, laminin, or
gelatin before cultivation.
Q2: Cell attachment on the stretch chamber is not consistent.
A2: There may be wrinkles or bubbles on the bottom surface of the strain chamber
when seeding cells.
Although the chamber is carefully made not to have
wrinkles on it, some products might have little wrinkles due to its thin structure. We
recommend the following steps.
Place a small volume of ethanol in a Petri
dish that is large enough to hold the strain chamber. Gently place the chamber in the
culture dish starting at one edge and moving toward the opposite edge of the chamber
to remove air bubbles between the dish and chamber. Allow the ethanol to evaporate
before spreading your cell suspension in the chamber.
Q3. Cell attachment on the stretch chamber was confirmed by microscopy. But the
cells detached from the chamber surface after stretching the cells.
A3: Try seeding your chambers at a lower concentration of cells. Over-confluent cells
generally adhere to neighboring cells rather than to the base matrix (dish surface).
When an excess amount of cells are put in a culture dish, the cells connect to each
other after growth. Such behavior of the over-confluent cells, which are often observed
in normal culture dishes, is even worse in the strain chamber.
A second possibility for cell detachment is that the cells were damaged by enzyme
treatment such as trypsin before seeding. The damaged cells sometime attach to
surfaces by non-specific binding and are not specifically bound to the extra-cellular
matrix coating on the chamber; therefore, time, concentration, and temperature for the
enzyme treatment should be optimized to reduce cell damage.
A third possibility is insufficient coating of the chamber preventing the cells from
attaching to the chamber. Longer coating time is recommended. Some researchers
coated the chamber with two or more kinds of the extra-cellular matrix materials to
increase binding effectiveness.
