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06/2024 – Handling Polarographic Dissolved Oxygen (DO) Sensors: A Comprehensive Guide

DO measurement

Polarographic dissolved oxygen (DO) sensors are essential tools in various fields, including biotechnology, environmental monitoring, and water treatment. These sensors measure the concentration of dissolved oxygen in liquids, providing critical data for process control and quality assurance. Proper handling and maintenance of polarographic DO sensors are crucial for accurate and reliable measurements. This article outlines key steps and best practices for managing these sensors effectively.

Understanding Polarographic DO Sensors

Polarographic DO sensors operate on the principle of electrochemistry. They consist of a cathode (usually made of platinum or gold) and an anode (often silver or silver chloride) immersed in an electrolyte solution and separated from the sample by a gas-permeable membrane. When a voltage is applied, oxygen diffuses through the membrane and is reduced at the cathode, generating a current proportional to the oxygen concentration.

Steps for Effective Handling of Polarographic DO Sensors

  1. Initial Setup and Polarization
    • Sensor Connection: Connect the DO sensor to the appropriate controller or meter according to the manufacturer’s instructions. Ensure all connections are secure to avoid signal interference.
    • Polarization: Before using a new sensor or after prolonged storage, it must undergo polarization. This process involves applying a voltage to the sensor, allowing it to stabilize. Typically, polarization can take between 6 to 24 hours. Follow the manufacturer’s guidelines for the specific polarization time required.
  2. Calibration
    • Zero Calibration (0% Oxygen): Perform this calibration in an oxygen-free environment. This can be achieved by using a zero-oxygen solution or nitrogen gas. Ensure the sensor reads close to zero nA, indicating no oxygen presence.
    • Span Calibration (100% Oxygen): Calibrate the sensor in an environment with known oxygen concentration, usually air (20.9% oxygen). The sensor should provide a stable reading, typically in the range of 40 nA to 100 nA, depending on the sensor model and conditions.
  3. Maintenance
    • Regular Calibration: Regularly calibrate the sensor to ensure accurate measurements. Frequency depends on usage conditions but should generally be done before each measurement series or at least once a week.
    • Membrane and Electrolyte Replacement: Periodically inspect and replace the membrane and electrolyte solution. A damaged membrane or depleted electrolyte can lead to erroneous readings.
    • Cleaning: Clean the sensor regularly to remove any biofouling or debris. Use appropriate cleaning solutions recommended by the manufacturer to avoid damaging the sensor components.
  4. Operational Tips
    • Temperature Compensation: Ensure the sensor is equipped with temperature compensation, as oxygen solubility varies with temperature. Many modern sensors include automatic temperature compensation.
    • Sample Handling: Avoid bubbles in the sample, as they can cause fluctuations in oxygen readings. Stir or mix the sample gently to ensure homogeneity.
    • Storage: When not in use, store the sensor in a protective cap filled with a storage solution or in an appropriate dry place. Follow the manufacturer’s recommendations for long-term storage.
  5. Troubleshooting
    • Unstable Readings: If the sensor provides unstable or fluctuating readings, check for air bubbles under the membrane, proper sensor polarization, and adequate calibration.
    • Low or No Signal: Ensure the sensor is properly polarized and connected. Check the membrane and electrolyte for any signs of damage or depletion.
    • Slow Response Time: A slow sensor response can indicate membrane fouling or aging. Cleaning or replacing the membrane can resolve this issue.

Conclusion

Handling polarographic DO sensors with care and precision is essential for obtaining reliable data in any application involving dissolved oxygen measurement. By following proper setup, calibration, maintenance, and troubleshooting steps, you can ensure that your polarographic DO sensor provides accurate and consistent results. Regular attention to these details will extend the life of your sensor and enhance the quality of your measurements, ultimately contributing to the success of your operations.

For further information or specific guidelines, always refer to the manufacturer’s manual and support resources.

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05/2024 – Enhancing Oxygen Transfer Efficiency in Bioreactors: Mastering kLa

gas bubbles

In the realm of bioprocessing, the volumetric mass transfer coefficient, or kLa, is a critical parameter that measures how effectively oxygen is transferred from the gas phase to the liquid phase in bioreactors. This coefficient is vital for ensuring that cultured cells receive the oxygen necessary for optimal growth and productivity. Here’s a closer look at what kLa entails and how it can be optimized to boost bioprocess efficiency.

Understanding kLa

kLa stands for volumetric mass transfer coefficient, where:

  • k is the mass transfer rate at the gas-liquid interface,
  • L indicates the transfer is occurring in the liquid phase,
  • a represents the surface area available for gas exchange.

The efficiency of oxygen transfer, as indicated by kLa, influences cell health and productivity directly. Insufficient oxygen transfer can lead to reduced cell growth and lower product yields, making kLa optimization a crucial aspect of bioprocess engineering.

Strategies to Optimize kLa in Bioreactors

Improving kLa involves enhancing the conditions and equipment used in the oxygen transfer process. Here are several effective approaches:

1. Increase Agitation Speed

Boosting the agitation speed in bioreactors enhances the mixing and increases the turbulence within the culture medium. This results in a larger surface area for oxygen to dissolve into the liquid, thus increasing kLa.

2. Enhance Aeration

Increasing the aeration rate by pumping more air or pure oxygen into the bioreactor raises the oxygen’s partial pressure, enhancing its solubility and transfer efficiency into the medium.

3. Utilize Pure Oxygen

Switching from air to pure oxygen can dramatically increase the oxygen concentration gradient between the gas phase and the liquid phase, enhancing mass transfer rates.

4. Optimize Impeller Design

Using impellers that are specifically designed for better gas dispersion can increase the effective surface area for mass transfer. Different types and configurations of impellers may be experimented with to find the most effective option for specific bioprocess requirements.

Check out bbi-biotech’s impeller designs in our bioprocess shop.

5. Reduce Liquid Viscosity

A lower viscosity in the liquid medium facilitates better mixing and enhances the dispersion of gas bubbles throughout the liquid. This can be achieved by adjusting the composition of the medium or its temperature.

6. Optimize Bubble Size

Smaller bubbles create a larger surface area relative to their volume, enhancing oxygen transfer. Spargers or diffusers that produce a fine bubble size can significantly improve kLa.

bbi-biotech offers micro spargers with various pore sizes and ring sparger with various hole sizes.

7. Control Environmental Conditions

Factors like temperature and pH can affect the solubility of oxygen in the liquid medium. Maintaining these within optimal ranges ensures higher solubility and better diffusion rates, thus improving the efficiency of oxygen transfer.

Conclusion

Optimizing kLa is essential for maximizing the efficiency of bioreactors by ensuring adequate oxygen transfer to support cell growth and productivity. By applying the strategies outlined above, bioprocess professionals can enhance the performance of their bioreactors, leading to improved outcomes and yields. This focus on efficient oxygen transfer is fundamental to the success and scalability of biotechnological applications.

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04/2024 – Enhancing Bioreactor Performance with Spinfilter Technology: A Deep Dive into Its Impact and Advantages04/2024 –

Introduction

In the world of biopharmaceutical manufacturing, particularly in the cultivation of mammalian cells, maintaining high cell densities and efficient operation are pivotal. One technological innovation that stands out in achieving these goals is the spinfilter—a specialized device designed for use in bioreactors operating under continuous perfusion conditions. This blog explores the fundamental aspects and benefits of spinfilters, drawing on a wealth of research to highlight their crucial role in modern bioprocessing.

Understanding Spinfilters in Bioreactors

A spinfilter is essentially a spinning cylindrical filter integrated within a bioreactor. It serves a dual purpose: retaining cells and facilitating high-density cell cultivation without the recurrent issue of filter clogging. Here’s a detailed look at the design and functionality of spinfilters and their impact on bioreactor efficiency:

Spinfilter Design and Function

At its core, the spinfilter features a cylindrical screen that rotates within the bioreactor. The screen’s openings are meticulously sized—slightly larger than the cells being cultivated—to efficiently retain them while allowing the culture medium to circulate freely. Optimizing the spinfilter’s rotational speed is critical to prevent clogging and ensure effective cell retention. This optimization helps maintain uninterrupted operation and enhances overall productivity Yabannavar, Singh, & Connelly, 1992.

Achieving High Cell Densities

Spinfilters are pivotal in preventing cell loss, thereby allowing bioreactors to operate at high perfusion rates. This capability is essential for achieving very high cell densities crucial for successful biopharmaceutical processes Yabannavar, Singh, & Connelly, 1994.

Reduction in Clogging

One of the traditional challenges in bioreactor operations is the clogging of the filter surface. By selecting appropriate screen sizes and fine-tuning the rotational speed, spinfilters significantly mitigate this issue. This not only reduces downtime but also cuts down on maintenance demands, making the bioprocessing workflow much more efficient Fraune, Meichsner, & Kamal, 1997.

Scale-Up Considerations

As bioprocessing operations scale from laboratory to industrial levels, the design and operational parameters of spinfilters must be carefully analyzed. This ensures that the efficiency and effectiveness of cell retention are maintained across different bioreactor sizes, a critical factor for successful scale-up Iding et al., 2000.

Conclusion

Spinfilters play an indispensable role in enhancing the performance of bioreactors. By efficiently retaining cells and minimizing issues like clogging, they help optimize the bioprocessing workflow, leading to higher productivity and reduced operational costs. Their importance becomes even more pronounced as bioreactor systems scale up and the demand for efficient, high-yield biotechnological processes grows.

Interested in integrating spinfilter technology into your bioreactors? Explore our high-quality spinfilters and see how they can benefit your bioprocessing operations here.

For more insights into biotechnology advancements and practical solutions, stay tuned to our shop at bbi-biotech.

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02/24 – Enhancing Bioreactor Technology with Advanced Sealing Solutions

Gekapselte Gleitringdichtung

At bbi-iotech, we are constantly striving to bring innovations and improvements to our bioreactor technologies that elevate operational efficiency and reliability for our valued customers. It’s with great enthusiasm that we announce a significant upgrade in our bioreactor designs, focusing on a key component that is pivotal for sterile operations and overall system performance: the mechanical seal in our bioreactor stirrer shafts.

Introducing Advanced Seal Technology

After a period of thorough evaluation and rigorous testing, we are integrating a state-of-the-art mechanical seal into our bioreactor stirrer shafts. This new seal technology is distinguished by its fully encapsulated design, marking a leap forward in seal solutions.

Key Features and Benefits

  • Enhanced Sterile Operations: The seal technology we’ve chosen is specifically designed for sterile applications. It guarantees the highest standards of hygiene and contamination control, which are paramount in bioprocessing and pharmaceutical manufacturing.
  • Minimized Cleaning and Maintenance: Thanks to its encapsulated design, the seal greatly reduces the need for regular cleaning and maintenance. This not only cuts down operational costs but also significantly lowers downtime, boosting productivity.
  • Durability and Reliable Performance: Engineered for durability, the seal comes with advanced coating options that ensure it withstands the demanding conditions of bioreactor operations. This translates to consistent performance and reliability over time.
  • Seamless Compatibility: We have conducted extensive compatibility tests with our bioreactor systems to ensure that these new mechanical seals integrate flawlessly. Stirrer shafts equipped with the new seals can be directly exchanged with older models, eliminating the need for any modifications.
Gekapselte Gleitringdichtung

Encapsulated Design: A Game Changer

The hallmark of this new mechanical seal is its encapsulated design, which shields the spring mechanism from direct contact with the process media. This innovative approach significantly diminishes the risk of fouling and accumulation of materials, a common challenge in bioreactors handling media with solids or high viscosity.

We are excited about the potential of this upgrade to set new standards in bioreactor technology and operational excellence. For more information or to discuss how these developments can benefit your operations, please don’t hesitate to get in touch.

At bbi-biotech, we are more than just a supplier; we are your partner in innovation, dedicated to advancing the field of biotechnology together.

Stay tuned for more updates as we continue to innovate and enhance our technologies for your success.

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02/2023 No More Downtime: Keep Your Bioreactors Running Smoothly with bbi-biotech’s Annual Maintenance

In the world of scientific research and production, bioreactors are the heart of many laboratories. Their performance can significantly influence the efficiency and output of your work. Understanding this, bbi-biotech is dedicated to providing specialized maintenance and operational support to keep your bioreactors running flawlessly.

Why Regular Maintenance is Crucial

Regular maintenance of bioreactors isn’t just about preventing breakdowns—it’s about ensuring consistent, optimal performance. Neglecting this crucial aspect can lead to increased downtime and costly repairs, ultimately delaying your projects and production. Our tailored maintenance solutions are designed to prevent these issues, allowing your lab to operate at its best.

What We Offer: Customized Maintenance Contracts

Our annual maintenance contracts cover everything your bioreactors need to maintain peak performance:

  • Comprehensive Inspections: We check all inlet and outlet ports, ensuring there are no blockages or leaks.
  • Seal and O-Ring Checks: Regular inspections prevent small issues from becoming major problems.
  • Sensor Calibration: Accurate readings are vital for precision in experiments and production processes.

These preventive measures are integral to efficient bioreactor operations and are all included in our customizable maintenance packages.

Tailored to Your Lab’s Needs

We recognize that each laboratory has unique needs. Whether you’re running prolonged cultures or require high-throughput production, we offer maintenance contracts tailored specifically for your operations. Our team works closely with you to understand your processes and provides solutions that best fit your requirements.

Beyond Maintenance: Training and Consulting

Ensuring that your equipment is in top condition is just the start. We also offer training and consulting services to help you maximize the efficiency of your bioreactors. Our experts are ready to assist you in optimizing your processes and troubleshooting any issues you may encounter.

Convenient, Cost-Effective Service

We aim to make bioreactor maintenance as convenient and affordable as possible. By signing up for a maintenance contract with us, you ensure continuous operation without the hassle of unexpected breakdowns and repairs.

Get Started Today

Don’t let bioreactor downtime disrupt your lab’s output. Contact us at shop@bbi-biotech.com to discuss your needs and how we can assist you. Our experienced team is eager to ensure that your equipment always performs at its best. For more information on our extensive range of bioreactor accessories and services, visit our accessory shop.

Act now to ensure that your bioreactors are always in perfect condition. Reach out today for your customized maintenance solution and keep your production moving smoothly.

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02/2023 Methanol Measurement in Pichia Pastoris Fermentation: Inline Probes and Practical Tips

Pichia Pastoris fermentation is a frequently used method in biotechnology to produce proteins and enzymes. However, fermentation brings some challenges, especially in terms of methanol production. In this article, we will focus on specific methods for measuring methanol during Pichia Pastoris fermentation and provide practical tips for measuring methanol in the bioreactor.

Methanol Production in Pichia Pastoris Fermentation

During fermentation, Pichia Pastoris produces methanol to promote its growth. However, methanol is toxic and at high concentrations can inhibit or even kill the cells. Therefore, it is important to monitor and control methanol production during fermentation.

Inline Probes for Methanol Measurement

One method for monitoring methanol production during Pichia Pastoris fermentation is inline probes. Inline probes continuously measure the methanol content during fermentation. There are several types of inline probes that can be used for methanol measurement, including spectroscopic probes and electrochemical probes.

Spectroscopic Probes

Spectroscopic probes measure the methanol content based on absorption spectra in the infrared region. The method is sensitive and accurate, but requires careful calibration.

Electrochemical Probes

Electrochemical probes measure the methanol content based on electrochemical reactions. The method is easy to handle and requires only minimal calibration. However, it is important to regularly clean and calibrate the probes to obtain accurate results.

Practical Tips for Methanol Measurement in the Bioreactor

In addition to using inline probes, there are other practical tips for measuring methanol in the bioreactor. One option is to take samples during fermentation. The samples can then be analyzed in the laboratory to determine the methanol content. Although this method is time-consuming and requires additional work, it is more accurate than measuring with inline probes. Another option is to use reference substance solutions. Reference substance solutions are added at the beginning of fermentation and serve as a reference for methanol measurement. Using reference substance solutions can minimize deviations in measurements due to impurities or other factors.

Conclusion

Methanol measurement in Pichia Pastoris fermentation is an important factor in controlling methanol production and ensuring successful growth of cells and production of high-quality biotechnological products. The use of inline probes is a useful method for continuously measuring methanol content. However, it is important to carefully select the method and regularly clean and calibrate the probes. Additionally, practical tips such as controlling the bioreactor, regularly monitoring and cleaning the measurement equipment, and calibrating probes and solutions can help ensure successful and efficient Pichia Pastoris fermentations

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06/2022 – Meet bbi-biotech at Analytica 2022 in Munich

bbi-biotech GmbH is pleased to announce that we will be present as an exhibitor at the world’s leading trade fair “analytica” in 2022. As the world’s largest meeting place for the industry, “analytica” offers a comprehensive range of topics from laboratory technology, biotechnology, life science and diagnostics to analytics and quality control – and bbi-biotech is in. Among other things, xCUBIO bioreactor will be show-cased, which can be used for a wide variety of biotechnological applications. The modular system results in a diverse range and enables the adaptation of the devices to the individual applications and ideas of our customers.

In addition, bbi-biotech is presenting its globally patented, sterile sampling systems “bioPROBE”, which enables automated integration of external analyzers into the “atline” process control. With the help of bioPROBE, liquid samples can be taken from bioreactors quickly, independently, without dead volume and transferred to any analysis device without endangering the sterility of the ongoing production process. Furthermore, the online integration of a glucose sensor will be shown, which is suitable for all vessel sizes and can be combined with the bioPROBE sampling system, thus combining sampling and measuring the glucose concentration in one step. The space-saving “add-on” offers real-time monitoring and thus contributes significantly to increasing the productivity, efficiency and reproducibility of your process. We are looking forward to welcome you at our booth 317 in hall B2. Discuss the feasibility of your ideas with our experts and let our products convince you on site.

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02/2021 – xCUBIO Glucose Sampling: No more offline glucose tests!

Work has been going on for 20 years to measure glucose during the process. Jobst Technologies developed a glucose flow sensor with which it is finally possible to detect glucose and also lactate and even to regulate it afterwards. For this purpose, sample is automatically and sterilely drawn from the culture vessel, passed through the sensor and a measured value is determined. We offer you the unique possibility to measure and record the glucose concentration in cell cultures or even in bacterial processes in real time. An intelligent control circuit makes it its business to monitor this value and to add glucose or another C-source as needed according to your calculations and wishes. This greatly reduces the number of faulty batches and makes the process more transparent. It can be calibrated to their medium and requires only a single sample.Due to the microfluidic design, only a few μl of a sample are necessary to guarantee precise results! The most important key data for the xCUBIO Glucose Sampling:

  • Measuring range 0 mM – 25 mM 0 g/l – 4. 5 g/
  • Measuring accuracy 0.01 mM
  • Temperature range 10°C-40°C
  • pH stability 6 – 8