Frequently Asked Questions

BioLector / Technical Information

What are the technical requirements for a BioLector installation?

The installation of a Biolector I requires:

  • A flat surface with a minimal load capacity of 45 kg
  • Dimensions (W x H x D): 690 mm x 405 mm x 490 mm
  • 2x power supply: 90-230 V, 50/60 Hz for the BioLector, and a laptop
  • 250 mL deionized water for the humidity control

The installation of a Biolector Pro requires:

  • A flat surface with a minimal load capacity of 40 kg for BioLector Pro and 37 kg for the Valve Control Unit
  • Dimensions (W x H x D):
    - BioLector Pro: 795 mm x 330 mm x 510 mm
    - Valve Control Unit: 735 mm x 370 mm x 510 mm
  • 2x power supply: 90-230 V, 50/60 Hz for the BioLector Pro, and a laptop
  • 250 mL deionized water for the humidity control
  • 3.5-6 bar (0.35-0.6 MPa) of compressed air

 

What is the essential difference between a BioLector I and a BioLector Pro?

In addition to all features of the BioLector I, the BioLector Pro offers the possibility of individual pH control and individual time or BioLector signal triggered feeding for each well.  

Which parameters can I measure with the BioLector in each well?

The BioLector I  and BioLector Pro is capable of measuring pH, DO and biomass. Furthermore, fluorescence can be measured via optical filter modules with excitation and emission wavelengths lying between 365 and 800 nm. Each module has a specific set of excitation and emission filters for the detection of fluorescent molecules, such as NAD(P)H, GFP, YFP, RFP or Riboflavin. By calibrating, the concentration of the molecules can be easily monitored online during every BioLector experiment.

What are the excitation and emission wavelengths for common fluorescence filter modules?

 

  • Biomass (λEx/ λEm): 620 nm/ 620 nm (scattered light)
  • pH (HP8) (λEx/ λEm): 470 nm/ 525 nm (phase measurement)
  • DO (Pst3) (λEx/ λEm): 520 nm/ 600 nm (phase measurement)
  • GFP (λEx/ λEm): 488 nm/ 520 nm (fluorescence intensity)
  • DsRed (λEx/ λEm): 550 nm/ 580 nm (fluorescence intensity)
  • NADH and NADPH (λEx/ λEm): 365 nm/ 450 nm (fluorescence intensity)
  • mCherry (λEx/ λEm): 580 nm/ 610 nm (fluorescence intensity)

The BioLector can be equipped with up to three additional customized filter modules. In total six different ones fit into the system.

What additional features can be added to the BioLector?

The addition of multiple BioLector modules is possible:

In total six different ones fit into the system.

What is the measurement principle of the biomass measurement?

Biomass is measured via scattered light with an "excitation" wavelength of 620 nm. The back scatter of the particles in suspension (cells) is collected and detected. Thus, the intensity of the collected scattered light correlates with the biomass concentration of the culture. Increasing biomass concentrations are reflected in an increasing signal of scattered light intensity.

What is the dynamic range of the biomass measurements?

Scattered light detection depends on shaking frequency, filling volume of microtiter plate well, microtiter plate type, particle size and shape of microorganism and media components.

In the BioLector I, the minimal detection value for the scattered light measurement is
> 100 NTU (nephelometric turbidity unit) which is correlated to an OD600 = 0.055 using the
AMCO CLEAR® TURBIDITY STANDARD*.

In the BioLector Pro, the minimal detection value for the scattered light measurement is
> 200 NTU (nephelometric turbidity unit) which is correlated to an OD600 = 0.11 using the
AMCO CLEAR® TURBIDITY STANDARD*.

* at 25 °C, 100µL and 800 rpm

 

 

What is the measurement principle of the DO optodes?

When excited with light from the LED the DO optode emits a fluorescent signal that is quenched in the presence of oxygen. The degree of quenching correlates to the dissolved oxygen concentration in the culture medium.

What is the dynamic range for the DO measurements?

The measurement range for DO is always between 0 and 100 % of saturated air in the culture medium with a resolution of up to 0.5 % and an accuracy of ± 5 %. Please check the calibration data sheet of your microtiter plate for further information.

What is the measurement principle of the pH optodes?

The pH optode consists, amongst other things, of a hydronium sensitive dye and a reference dye. The higher the concentration of hydronium ions (low pH value), the lower the fluorescence of the pH-sensitive dye. The combination of reference- and pH-sensitive dye results in a measurable phase shift of the responding signal. The patented DLR method enables internally referenced measurements: A combination of different fluorescent dyes detects the intensity changes in the time domain.

What is the dynamic range for the pH measurements?

The measurement range is microtiter plate lot number dependent but always within a range of pH 4.5 and 7.5, with a resolution of up to 0.02 pH and an accuracy of ± 0.1 pH units. Please check the calibration data sheet of your lot for further information.

What is the temperature range that can be set?

The BioLector is equipped with Peltier elements for temperature control in the incubation chamber. In the BioLector I the temperature can be controlled between between 5 °C below room temperature (via active cooling) and 50 °C. In the BioLector Pro the temperature range is between room temperature and 50 °C.

Can I run cultivations with the BioLector in fed-batch mode?

Yes, fed-batch cultivations can be realized with the BioLector Pro. The system performs high-throughput cultivations in batch or fed-batch mode together with online monitoring of biomass, pH, DO, and fluorescence.

If the BioLector is integrated into a liquid handler, the RoboLector, fed-batch cultivations can be realized, too. The RoboLector is a unique automated fermentation platform combining the high-throughput fermentation and online monitoring capability of the BioLector with precise and accurate automated liquid handling.

For more information regarding the performing of fed-batch cultivations in the RoboLector, please refer to:

 

How can the scattered light readings of the BioLector be correlated for example with optical density, cell dry weight or other biomass concentrations units?

To correlate the scattered light readings with e.g. optical density (OD600), begin by measuring the scattered light values of a serial dilution with known biomass concentrations in the BioLector. Then plot the scattered light intensities against the offline readings of e.g. a spectrophotometer.

Please inquiry our application note for the calibration of biomass.

Is it possible to scale up from BioLector to fermenter?

Yes, scalability from microtiter plate to bench top fermenter is one of the essential characteristics of the BioLector technology. Therefore, the BioLector can be used e.g. for strain, media or promoter screenings in a micro scale and to translate the results then to liter-scale fermentations.

Please refer to: 

 

 

 

Microfluidics

What is the functionality principle of the liquid delivery of the BioLector Pro?

The liquid delivery is realized through microfluidic channels in a microfluidic chip in the bottom of the microfluidic microtiter plate developed by m2p-labs.

→ Watch the video

Which types of feeding profiles can be realized with the BioLector Pro?

The BioLector Pro can realize a constant, a linear, an exponential or a signal-triggered feed. For the signal-triggered feed, any signal measured by the BioLector Pro can be used to activate the feeding.

Which signals can be used as a trigger to control feeding or the pH control?

Any signal measured by the BioLector Pro, such as biomass or dissolved oxygen (DO), as well as the current well volume or the experiment time, can be used to activate the feeding trigger or the pH control.

Is it possible to run a pH-profile with the BioLector Pro?

Yes, the BioLector Pro can adjust the pH to different values over the course of a cultivation according to a pre-programmed pH profile.

What is the dynamic range of the pH control?

The pH control can be realized between pH 6 - 7.5, depending on microorganisms and media.

A two-sided pH control can be set up, when both of the reservoir lines are filled with the pH regulation agents. In line A, the reservoir wells are filled with acid. In reservoir line B, the wells are filled with base.

If one reservoir line is used as a feeding line, then just a one-sided pH control is possible. There is no pH control possible, if both of the reservoir lines are used as a reservoir for feeding.

RoboLector

What types of RoboLector devices are available and how do they differ from each other?

Three different RoboLector variants are available:
RoboLector L-2, RoboLector L­‑4 and RoboLector XL-8. 

Both RoboLector L devices offer up to 16 SBS footprint sized MTP slots, the RoboLector XL up to 20. RoboLector L-2 is equipped with one disposable tip adapter (DiTi) and one washable Teflon coated tip. RoboLector L-4 possess 1 DiTi adapter and 3 washable tips, RoboLector XL is equipped with 2 DiTi adapters and 6 washable tips.

What are the measurements of a RoboLector?

Dimensions with a BioLector I (W x H x D):

  • RoboLector L: 1625 x 935 x 780 mm
  • RoboLector XL: 1850 x 935 x 780 mm

Dimensions with a BioLector Pro (W x H x D):

  • RoboLector L: 1830 x 935 x 780 mm
  • RoboLector XL: 2055 x 935 x 780 mm

 

Which type of BioLector can be integrated into the RoboLector?

All BioLector devices (BioLector I, BioLector II, BioLector Pro) can be integrated into a RoboLector.

Which trigger signals can be used to elicit pipetting actions?

All online monitored BioLector signals (both calibrated and not calibrated) can be used to activate pipetting steps such as sampling or the dosing of pH regulation agents and feeding solutions. Furthermore, the pipetted volume, the current filling volume of a well, the process time and the time since the activation of a previous pipetting event can be used as trigger set points for sampling or dosing actions with the RoboLector.

Which kind of pipetting actions can the RoboLector achieve?

A RoboLector can prepare e.g. cultivation media either on the worktable or directly within the BioLector. Furthermore, the RoboLector is able to add liquids, such as pH regulation agents, feeding solutions or inductors into the MTP cultivated in the BioLector. Finally, the RoboLector can take samples from the BioLector MTP during running experiments.

Can I adjust RoboLector worktable layouts individually by myself?

No, unfortunately it is not possible to change the allocation of the items on the worktable by yourself. Every customer is provided with up to four different fix worktable layouts that can be selected freely in the RoboLector Agent settings. The worktable layouts are put together individually for every customer according to his or her needs. Nevertheless, it is always possible to order more additional layouts. Please contact our support or sales team in case of interest.

How can sterile conditions be maintained in the RoboLector?

m2p-labs developed specific sterile MTP cover (F-GPRS48-10 and F-GPRSMF32-1) to maintain sterile conditions in automated cultivation processes. These foils are equipped with a silicone layer on top that has a pre-cut slit and a venting hole for gas exchange in each well. The pre-cut slits serve as entry points for the pipetting needles. After removing a needle from a slit, it seals itself because of the silicon material. Furthermore, different washing options are available to decontaminate and clean the pipetting needles. To guarantee sterility over all working conditions we strongly recommend using a biosafety cabinet.

Do I need to place the RoboLector into a biosafety cabinet?

We have customers working successfully without biosafety cabinets. However, we strongly recommend using biosafety cabinets of at least class II to help keeping your bioprocesses sterile. Using a biosafety cabinet is also much safer since you cannot reach as easily onto the worktable while the liquid handler is moving as would otherwise be the case without a sterile enclosure.

What are the pipetting times of a RoboLector?

A RoboLector XL is e.g. able to inoculate all wells of an entire 48 well microtiter plate in the BioLector incubation chamber within only 4.9 minutes (pipetting volume 10 µL, washing volume 100 µL). The pipetting time is strongly dependent on a lot of different factors, such as the number of wells, the pipetting volume, the washing volume, the washing mode (Simple Cleaning or Extended Cleaning) and the number of tips your RoboLector is equipped with. Please contact our support team if you have further questions regarding the pipetting time. We have estimated the pipetting time of a number of experiment setups and are looking forward to helping you!

Which types of microtiter plates can I use in the RoboLector?

You can use both MTPs provided by m2p-labs (FlowerPlate and Round Well Plate) as target MTP for the media preparation as well as for BioLector experiments. The MTPs used by the RoboLector for dosing and sampling can be found in the online shop of Ritter GmbH (Schwabmünchen, Germany):

Dosing MTP (www.ritter-online.de/en/medical/riplate_sw/index.php):

  • Riplate® SW 48, PP, 5 mL (art.no. 43001-0062)
  • Riplate® SW 48, PP, 5 mL, sterile (art.no. 43001-1062)

Sampling MTP (www.ritter-online.de/en/medical/riplate/index.php):

  • Riplate® RW, PP, 1 mL (art. no. 43001-0016)
  • Riplate® RW, PP, 1 mL, sterile (art. no. 43001-1016)

 

Disposables /// Microplates

When should I use the Round Well Plate and when the FlowerPlate?

The Round Well Plate and the FlowerPlate provided by m2p-labs are two 48 well microtiter plates based on standard SBS footprint. The Round Well Plate is ideally suited for cultivating shear sensitive cells (for example filamentous microorganisms and plant cells). The FlowerPlate is mostly applied in cultivations of microbial cells (bacteria, archaea, yeasts, fungi, etc.). The name is based upon its flower-like shaped MTP wells. The flower shape has been proven to be the most suitable well geometry to increase the range of oxygen transfer rates (OTRs): Funke et al., 2009.

What is the OTR that can be realized with the Round Well Plates and the FlowerPlate?

In the FlowerPlate much higher OTR are realized than in the Round Well Plate because of the flower shaped wells (baffles). The OTR depends mostly on shaking speed and filling volume: The higher the shaking speed and the lower the filling volume, the higher the OTR. The approximate range of the OTR in a FlowerPlate MTP lies around 30 – 110 mmol/L/h. In the Round Well Plate OTRs between 5 – 25 mmol/L/h can be reached.

What are the recommended filling volumes in the wells of a 48 well microtiter plate?

The filling volume depends on microtiter plate type and shaking frequency. After selecting if you want to use a Round Well Plate or a FlowerPlate, you can check the OTRs resulting from different combinations of shaking frequency and filling volume on the respective MTP’s data sheet. Filling volume and the shaking speed have to be selected carefully. If both are e.g. set high, the culture will spill over. If you reduce the shaking speed, make sure not to set it too low due to sedimentation effects. Adequate ranges of shaking speed and filling volumes are as follows:

FlowerPlate

  • Shaking frequency: 800 rpm/ Filling volume: 1500 µL
  • Shaking frequency: 1500 rpm/ Filling volume: 800 µL

 
Round Well Plate

  • Shaking frequency: 600 rpm / Filling volume: 2400 µL
  • Shaking frequency: 1000 rpm / Filling volume: 1500 µL

What are the maximal allowed shaking frequencies the Round Well Plate and the FlowerPlate?

The Round Well Plate should be used only up to 1000 rpm and the FlowerPlate up to 1500 rpm.

Disposables /// Sealing Foils

What different kinds of sealing foils are available?

 

  • F-GP-10: A basic sealing foil consisting of a single gas permeable non-woven layer for maintaining the sterility of the microtiter plate content and to allow uniform gas exchange.

  • F-GPR-10: A two-layer sandwich MTP cover consisting of a top layer (non-gas permeable PP foil with venting holes for evaporation reduction) and a bottom layer (F-GP-10).

  • F-GPRS48-10: A three-layer sandwich MTP cover consisting of a top layer (2 mm silicone mat), an intermediate, non-gas permeable layer with venting holes and a bottom layer (F-GP-10). Both the silicon layer and the middle layer contain venting holes for a uniform gas exchange. The silicon layer has additional self-sealing pre-cut slits that can be penetrated either manually by a syringe or automatically by the washable steel needles of a liquid handling robot (RoboLector).
     
  • F-GPRSMF32-1: A three-layer sandwich MTP sealing foil similar to F-GPRS48-10 developed for the usage of the RoboLector Pro system. Both MTP cover are identical except for the venting holes and pre-cut slits in the rows A and B that are exchanged in the F-GPRSMF32-1 foil by central air holes above the wells so that the necessary air pressure for the microfluidic system can be applied to the MF MTP.

 

How can I reduce evaporation without limitation in gas exchange (headspace/incubation chamber) by using sealing foils?

The evaporation rate without using a sealing foil is about 35 % per day* (based on weight). The basic sealing foil (F-GP-10) is suitable for short term cultivations. Using this foil, the evaporation rate can be reduced to 5-8 % per day*. For long term cultivations, a two-layer sandwich foil (F-GPR48-10) is available that reduces the evaporation to 1-2 % per day. A third and fourth type of sealing foils (F-GPRS48-10 and F-GPRSMF32-1) permit sampling and dosing steps during long term cultivations while reducing the evaporation to 1-2 % per day* as well.

* FlowerPlate, VL = 1000µL, T = 37 °C

Disposables /// Software

How can I visualize and analyze the measurement results of a BioLector experiment?

You can monitor all measurement results online in the BioLection. The results are updated after every measurement cycle automatically. For a general overview the BioLection allows to display all measurement signals simultaneously. For a more detailed data evaluation the measurements can be exported to a pre-formatted Excel template which converts the data into diagrams (only for BioLector I) or to an Excel compatible file that you can edit easily by yourself.

How many BioLection software licenses do I get when I purchase a BioLector?

If you buy a BioLector system, you can install the BioLection software on every computer used in your department.

What are the system requirements to work with the BioLection?

The BioLection software can be installed on Windows systems (Windows 7 and 10). The processor must have at least 1 GHz (Intel i3 or equal). The minimal random access memory is 4 GB RAM. The monitor needs a resolution of 1,280 x 720 pixel or higher. To connect your computer to the BioLector, your computer requires a working network connection.

 

///   BioLector®, RoboLector® and FlowerPlate® are registered trademarks.