Frequently Asked Questions

BioLector I

What are the technical requirements for a BioLector installation?

 

  • Flat surface with a minimal load capacity of 45 kg
  • Dimensions (W x H x D): 79,5 cm x 33,3 cm x 47 cm
  • 2x power supply: 100-240 V, 50/60Hz BioLector, and laptop
  • Humidity control: 250 mL deionized water

 

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

Every BioLector is capable of measuring pH, pO2 and biomass. Furthermore, fluorescence can be measured with optical filters by excitation and emission between wavelengths from 365 nm to 800 nm. These optical filters have a fixed wavelength for excitation and emission parameters such as NAD(P)H, GFP, YFP, RFP and the riboflavin concentration can be followed with the BioLector.

What are the excitation and emission wavelengths for (pH, pO2 and biomass) common fluorescence filters?

 

  • Biomass (λEx/ λEm): 620 nm/ 620 nm (scattered light)
  • pH (λEx/ λEm): 470 nm/ 525 nm (phase measurement)
  • pO2 (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 modules is possible:

  • O2 up-regulating module for the up regulation of oxygen up to 35%
  • O2 down-regulating module for the down regulation of oxygen down to 2%
  • CO2 up-regulating module for the fermentation with a CO2-controlled gas atmosphere
  • Anaerobic cultivation set for cultivation under anaerobic conditions

In total six different ones fit into the system.

What is the measurement principle of the biomass measurement?

Biomass is measured via scattered light at an excitation of 620 nm. The back scatter from the particles in suspension (cells) is collected and counted by a photomultiplier. 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. With the scattered light readings of the BioLector no dilutions are required to follow the biomass concentration over the course of most fermentations.

What is the dynamic range of the biomass measurements?

Scattered light detection depends on shaking frequency, filling volume of cavity, microplate type, particle size and particle shape of the microorganism and media components.

When correlating the scattered light signals of the BioLector with optical density the measurement range is between OD600 of 0.2 and 650 [-] and with cell dry weight between 0.1 - 100 g/L for E. coli in FlowerPlate.

What is the measurement principle of the pO2 optodes?

When excited with light from the pO2 LED the pO2 optode emits a fluorescent signal that is decreased or quenched in the presence of oxygen. The degree of quenching correlates to the partial pressure of oxygen in the matrix.

What is the dynamic range for the pO2 measurements?

The measurement range for pO2 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 lot for further information.

What is the measurement principle of the pH optodes?

The pH optode consists 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.

What is the dynamic range for the pH measurements?

The measurement range is lot number dependent but always within pH 4.5 and 7.5, with a resolution of up to 0.02 pH and an accuracy of ± 0.25 - 0.1 pH. Please check the calibration data sheet of your lot for further information.

What is the temperature range can be set?

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

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

Yes, fed-batch cultivations can be realized with the Media Development Kit provided by m2p-labs. This media kit binds a C-source in a polysaccharide matrix that enzymatically releases the C-source over time.

If the BioLector is connected to a liquid handler (RoboLector I), fed-batch cultivations can also be realized. The RoboLector I is an automated fermentation platform that combines the BioLector with an automated liquid handler.

Please refer to:

 

How can the scattered light readings of the BioLector be correlated to for example optical density, cell dry weight or others?

To correlate the scattered light readings of the BioLector to, e.g., optical density, the scattered light intensity of a serial dilution of samples with known biomass concentrations are measured with the BioLector and a linear correlation can be generated by plotting the scattered light intensities over the offline readings of optical density, for example.

Is it possible to scale up from the BioLector to a fermenter?

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

Please refer to: 

 

 

 

BioLector Pro

What are the technical requirements for a BioLector Pro installation?

 

  • 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: 79,5 cm x 33,3 cm x 47 cm
    - Valve Control Unit: 60 cm x 47,8 cm x 45 cm
  • 2x power supply: 90-230 V, 50/60 Hz BioLector PRO, and laptop
  • Humidity control: 250 mL deionized water
  • 3.5-6 bar 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 for each well and individually controlled feeding at individual feeding rates for each well. 

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

The liquid delivery is realized through microfluidic channels and controlled by air‑operated micro valves imprinted into a microfluidic chip at the bottom of a m2p-labs microfluidic microtiter plate (MTP).

→ Watch the video

Which feed 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.

Is it possible to define or stop a feed or the pH control?

Yes, the BioLector Pro can define or stop a feeding or the pH control. Activation triggers or stop conditions can use any signal measured by the BioLector Pro.

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, dissolved oxygen, or time, can be used to control the feeding or the pH control.

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

Yes, the BioLector Pro can realize a time controlled pH-profile.