New Model Concept Workstation Oxygen Test Report

The Concept Series Workstations have been recently remodelled. This report details the oxygen concentration throughout the work area within the workstation in anaerobic mode to ensure proper performance. These workstations will achieve less than 10 ppm Oxygen, and will return to the normal working oxygen level efficiently following operation of the sleeves, Single Plate Entry System (SPES), or interlock chamber.

Introduction

Baker Ruskinn design and manufacture workstations for the anaerobic microbiology, cell biology, stem cell and regenerative medicine markets. These workstations have historically controlled temperature, humidity, Oxygen, and Carbon Dioxide concentration. As technology and science develops, our workstations will too, grow. This new upgraded model of the Concept line of workstations have been redesigned to meet and exceed these new expectations, one of which is to provide and maintain an anaerobic environment, where there is a lack of Oxygen. It is required for the Oxygen (O₂) level to be less than 20 ppm (0.002%).

Methods

The Concept 400 workstation was connected to standard supply gasses – H₂N₂ and N₂. The Southland Sensing OMD-501D Trace Oxygen Analyser, and Southland sensing TO2-2X PPM Oxygen Sensor were calibrated using N6 nitrogen gas (>99.9999% purity) and then placed inside the workstation.

The workstation was placed into Gas Control mode as per the user guide, and upon completion of the gas mixing cycle the first O₂ measurement was recorded at the intervals of 0, 1, 2, 4 and 24 hours. Following the sample at 24 hours, operations of glove port entry, SPES and interlock were performed, and the maximum oxygen level was recorded, and the time taken to recover to pre-operation oxygen ppm levels was measured.

Results

Conclusion

It can be demonstrated that:

The workstation oxygen level recovers to less than 20ppm within 1 hour of completion of the Gas Mixing cycle and that the working oxygen level of the standard Concept Workstation is less than 10ppm.
With the use of the 4 catalyst option (Concept <5ppm Optional Accessory, part number 262-499), a working oxygen level of less than 5ppm is achievable.
Oxygen concentrations of less than 10ppm are achievable when using concentrations of 5% or 10% Hydrogen. However, it should be noted that the recovery times following operation of the Sleeves, SPES or Interlock are marginally slower when using 5% H2 concentrations.
Entry via the Interlock is less disruptive to oxygen levels than entering via the Single Plate Entry System (SPES). This is due to the interlock purging mechanism using nitrogen to provide a low-oxygen isolation barrier to the room atmosphere, and the purging process removing the oxygen contained in the headspace of the 90mm plate.