FAQs About Our Cell Stretching Bioreactors

Flexcell® has a Publication Database on our publications page that lists the bibliographies for some of the research conducted using our equipment. The list is categorized by type of equipment used and by cell type.

BioFlex®, HT BioFlex®, and UniFlex® plates are used to culture cells in monolayer. Tissue Train® culture plates are used for creating 3D bioartifical cell-seeded constructs.

BioFlex®, HT BioFlex®, and Circular Foam Tissue Train® plates can be used during application of equibiaxial tension. Linear and Trapezoidal Tissue Train® plates as well as UniFlex® plates are used during application of uniaxial tension.

Strain is applied to cells via vacuum deformation of the silicone elastomer growth substrate in the rubber-bottomed culture plates as depicted in the schematic below (Figure 1). Please also see our applications page about Applying Mechanical Load to Cells in Monolayer Culture and Tech Report 101: Loading Stations™. Quantification of Strain on the Membrane Surface for further information.

Yes! Flexcell® periodically has sales on equipment and consumables. Please contact Flexcell®'s Sales Department for current promotions.

Flexcell®'s on-line store only accepts credit card payments. If you wish to use another form of payment, please contact Flexcell® directly.

Flexcell® products are sold worldwide. Flexcell® International serves the USA and Canada. Europe is served by Dunn Labortechnik. Bio Excellence International Tech Co., Ltd. serves mainland China, Hong Kong, Macao, Malayasia and Singapore. Taiwan's distributor is Nature Opera. South Korea distributor is LeeBaeg Scientific Co.,Ltd. India's distributor is Medi Analytika. Brazil's distributor is Sellex. Customers from these regions should contact their local distributor for all order inquiries.

If your lab is located in the USA or Canada, we have 6 and 12-month renewable lease options. Please contact Flexcell®'s Sales Department at info@flexcellint.com for further information.

If your lab is located in the USA or Canada, we offer a 6-week complimentary trial period for all equipment.

This may be caused by plating too many cells. Plate with a lower cell density. If the cells are not confluent, they will form a matrix with the collagen (or other matrix coating) attaching more securely to the growth surface.

The grease can be removed with the following protocol after the cells have been fixed:

1. Using a dry cotton swab, wipe off as much of the excess lubricant as possible. This may require a couple of swabs. Only a thin film of lubricant should remain on the membrane surface.
2. Wet the tip of a new cotton swab with a mild cleaning solution such as Formula 409, window cleaner, or hand soap. Rub the wet swab gently over the entire surface of the well. Repeat with a new cotton swab and fresh cleaning solution as necessary to remove all residual lubricant from the membrane surface.
3. Rinse the cleaned surface with deionized water using a spray, wash, or dispensing bottle.
4. Blot the surface dry with a Kimwipe or other lint-free wipe.

Also, please see Tech Report 202 for more techniques on viewing cells on Flexcell® culture plates.

Please see Tech Report 106: Matrix Bonded Growth Surfaces. Growing Cells in a More Natural Matrix Environment, which discusses the various matrix coatings available on Flexcell®'s culture plates.

Yes! Please see Tech Report 202: Viewing Cells on Flexcell®'s Culture Plates. Light and Electron Microscope Techniques and Immunofluorescent Imaging. NOTE: Mounting medium needs to be water based.

The plates you received have a different calibration file from previous plates. If your system has not been updated with the new calibration files, they you will need to contact Flexcell® to get the software update for your system. Please be sure to include your unit serial number when contacting Flexcell®.

1. Shake or tap the tubing to release the air bubbles.
2. Turn the pulse dampeners upside down and allow them to fill to ¾ full. Then, turn the pulse dampeners the correct way around and allow the medium to flow through the system.

Leaking pulse dampeners are usually caused when the pulse dampeners have been autoclaved. The plastic becomes soft and slightly misshapen, so when the quick-disconnects are re-attached, the fit is not as tight and leakages can happen.

Make sure that:

1. All 12 o-rings (6 on the top and 6 on the bottom) of the Streamer® are present.
2. There is Teflon tape on all threaded quick-disconnects.
3. The top and bottom of the Streamer® are securely closed.
4. The quick-disconnects are "locked" into place.

Since the Streamer® is made of stainless steel, using any other screws other than the supplied brass screws will cause the screws and the Streamer to fuse together.

No, although there is a PUMP CONTROL socket on the rear of the FlexLink®, it is not electrically connected to the system. We do not sell a standalone air compressor but recommend using a compressed air source capable of producing 12 PSI (83 kPa) of pressure at 0.9 cfm (25.5 L/min).

If moisture is seen in the Flex Out or Flex In tubing coming from the baseplate in the incubator, make sure water traps are installed between the baseplate and the FlexLink® controller. Water traps should be installed at a height lower than the FlexLink®. Check water traps periodically for accumulated moisture. Empty the water traps when any water can be seen in the traps.

Moisture condensation in the tubing coming from the baseplate indicates there may be a leak or poor seal on the baseplate. Check to make sure all 4 slots of the baseplate are occupied by a gasket and BioFlex® plate. Check the perimeter of the bottom of the baseplate for any leaks due to baseplate warping. If the baseplate is warped due to prolonged exposure to high temperatures, you may need to replace the baseplate.

Moisture accumulation in the FlexLink®'s Flex In line can be caused by excessive water vapor in the atmosphere of the operating environment. If possible, monitor and reduce the relative humidity of the room where the FlexLink® is located. Relative humidity should be maintained below 40%. If moisture is seen in the Flex In tubing coming from the FlexLink®, run the drying regimen with the drying filter connected to Flex In and Flex Out ports on the back of the FlexLink®.

If moisture still accumulates in the FlexLink® tubing, contact Flexcell® for further technical assistance.

This problem is likely due to a poor gasket seal on the BioFlex® baseplate. See the solution to Problem 1 to correct this. Be sure to empty the water trap frequently if you are having this problem. Water accumulation in the controller can damage the valves. If the baseplate is sealed and the problem still continues, try placing another water trap inline for safety purposes and contact Flexcell®.

When vacuum is pulled to expand the silicone membranes at the bottom of the BioFlex® wells, the volume of the well increases, pulling air into the well from the atmosphere. When the membranes contract, the air is pushed back out. Because of this cyclic airflow during any experiment, the evaporation rate in the BioFlex® wells will increase. The only solution to this problem is to use more cell medium.

The software has a limit on the number of cycles that can be entered into any given step (65, 535; see page 12 of the manual). If you program a regimen with a frequency high enough to require more than 65,535 cycles to go for the amount of time that you wish to run it, the software will give you an "invalid entry" error. You will need to make an additional step to run the full regimen. This will not create any breaks in the regimen. Simply divide your total time in half (or as many times as is necessary) and make two steps with the same parameters. See page 12 of the manual for instructions on programming additional steps.

Remove the "sys" vacuum line at the back of the controller and check to be sure that there is vacuum coming through the line. Check the "vent" port at the back of the controller to see if air is moving in or out. If not, it is possible that the valves are locked or stopped up. Try applying positive pressure to the vent port to free the valves. If the "vent" port is breathing and the plates are flexing, the problem is likely with the computer and should be reported to Flexcell®.

Symptoms:

a. System is not performing to specified parameters; i.e., not reaching maximum %elongation entered in regimen

b. Water trap is filling up with water quickly during use with incubator

Test to determine if this is the problem:

If you are experiencing symptom a, there could also be a leak elsewhere in the system. To narrow its location, run a regimen with the baseplate and take note of the max and min %elongations. Disconnect the quick disconnects from the baseplate and connect them together. Take note again of the max and min %elongations. They should change a little because of the decrease in system volume, but if you were originally having outputs that were significantly different from the inputs, it should go near (maybe somewhat above) your original inputs. The wave will also likely be somewhat choppy because of the low volume. If your outputs were originally only slightly lower or higher than your inputs, the problem is likely not a leak but calibration. Call Flexcell® for calibration instructions. If the output max %elongation increases significantly when the quick disconnects are connected together, the leak is most likely in the baseplate. If not, check the vacuum connections at the back of the controller.

Flexcell® can upgrade your current system. Please contact Flexcell® to learn more about our options for upgrading.

a. Make sure the FlexLink® is powered ON.

b. Make sure the Ethernet cable is connected between the FlexLink® and the computer.

c. The IP address settings might have been changed by your institution upon set up in the laboratory. Please contact Flexcell® if you think this is the case.

This error results from assigning a regimen to a user that does not have a regimen created under his/her name. Either create a regimen for the user or delete the user and re-assign the regimen to a valid user.

a. Check to ensure there is no vacuum leak at the baseplate:

1. Check that the gaskets are flatly seated in the wells.
2. Make sure all 4 baseplate wells are being used.
3. Re-run the regimen while initially applying hand pressure to start the seal between the plates and gaskets.
4. Place the Plexiglas cover and, if needed, additional weights (up to a total of 10 lbs) on top of the Plexiglas cover.

b. Check to ensure that you have downloaded your regimen to the correct Platform.

c. Check the tubing to ensure there is not a kink.

d. Check the tubing length. The tubing should be cut as short as possible with enough extra length so that the tubing is not strained.

e. Contact Flexcell if any of the above do not resolve the issue.

Connect the Drying Filter and run the Drying regimen (as described in the manual). If the issue still persists, please contact Flexcell®.

If you are using the FX-6000™, FX-5000™, Flex Jr.™, FX-4000™ and FX-3000 Tension System, see response below. If you are using an older model, please contact Flexcell®.

a. Try lowering the frequency of the regimen to allow the FlexLink® enough time, per cycle, to intake and exhaust the correct amount of atmosphere.

b. Check to ensure there is no vacuum leak at the baseplate:

1. Check that the gaskets are flatly seated in the wells.
2. Make sure all 4 baseplate wells are being used.
3. Re-run the regimen while initially applying hand pressure to start the seal between the plates and gaskets.
4. Place the Plexiglas cover and, if needed, additional weights (up to a total of 10 lbs) on top of the Plexiglas cover.

c. Check the Water Traps, Flex In and Flex Out tubing for any moisture collection. Connect the Drying Filter and run the Drying regimen, if needed.

d. Check to ensure that the vacuum source is producing a constant pressure of -90 to -100 kPa. If using an oil-based pump, check to ensure that the oil is not dirty.

e. Contact Flexcell® if any of the above do not resolve the issue.

Please see Tech Report 109: Using Additional FlexLinks® for the schematics on connecting additional FlexLinks®. Please also see the video Connecting Two Tension FlexLinks® to One Computer on our Instructional Video page.