@misc{9226039,
  abstract     = {{As the market for biopharmaceuticals grows, the demand for continuous downstream pro-cessing (DSP) increases. This thesis tackled one of the key factors in successfully creating a continuous chromatography process: the ability to have an automated supply of complex buffer solutions. It aimed to develop and evaluate a Buffer Preparation Unit using an ÄKTA Pure machine, as well as the development of a custom Graphical User Interface to increase the usability of the system. This is done through the combination of the physical configura-tion of the hardware and the digital implementation of it in Orbit, a custom Python-based software architecture. 
The hardware was physically configured to draw from 12 distinct stock solution to mix 10 specific buffers used in the DSP. To bypass the limitations of the standard control software, operations were executed via an OPC UA network using Orbit. Furthermore, the GUI was developed to centralize control of the system, allowing operators to execute pre-defined rec-ipes, automatically calculate the volumetric ratios for manual buffer blends, monitor real time Quality Assurance data, and perform some basic maintenance on the system.
System evaluation identified two main challenges in the system. Firstly, the narrow inner diameters of the multi-valve configuration introduced cavitation during the mixing phase of the buffer preparation, capping the flowrates during this phase to 18-25 ml/min, depending on the position of the buffer flask. While this does not pose a big problem in the stand-alone system, it introduces limitations to up-scaling and integration with the rest of the DSP. Sec-ondly, the internal pH sensor of the system was found to have a static error and relatively large deviations in its readings, making it unreliable which necessitates the use of an exter-nal sensor for measuring pH during quality control. 
The thesis concludes that the developed BPU shows promise in being used in a real-life set-ting, despite its physical limitations. With the developed GUI combined with the BPU’s ability to automatically prepare buffers on demand, the system has potential to reduce the need mor manual buffer preparation and with further work, it may be integrated into the rest of the DSP, generating a truly automatic buffer supply for the process.}},
  author       = {{Sundström, Axel}},
  language     = {{eng}},
  note         = {{Student Paper}},
  title        = {{Automatic buffer preparation system for downstream processes}},
  year         = {{2026}},
}