Bio-Rad Profinia™ Protein Purification Instrument - Manual (Page 66)

The lower part of the Run in Progress screen shows the real-time data:
• Real-time data at — system clock time. The date and time setting is available in the
Data/Utilities section accessed from the home screen
• Flow rate — flow rate of the current step (displayed in ml/min)
• Collection — in which fraction tube the system is diverting output from the current step
• UV cartridge — appears as UV cartridge 1 when fluid goes through cartridge 1, and
switches to UV cartridge 2 when fluid goes through cartridge 2, displayed in
absorbance units (AU)
Note: Automatic peak detection is activated for specific elution steps. When Profinia
firmware is actively looking for the peak, a light bulb icon is displayed immediately in front of
the UV cartridge line. For details on automatic peak detection, see section 6.8.2.
• Conductivity — value is given in mS/cm
• pH — value appears when a pH monitor (optional) is connected to the Profinia system
6.8.2 Peak Detection
Affinity and desalting protein peaks are identified using an automatic peak detection algorithm
that is active during elution steps on the Profinia instrument. In addition to automatic peak
detection, the option to manually detect and divert the protein peak is also available during
affinity and desalting elution step(s). When manual peak detection is available during affinity
and desalting elution steps, the manual peak detection button displays on the Run in
Progress screen. Once a peak is detected either automatically or manually and the next
elution step is started, the manual peak divert button displays. For the vast majority of
proteins, automatic peak detection is the preferred and most robust route for peak collection.
Automatic Peak Detection
Automatic peak detection is an essential feature for identification, diversion, and collection of
the eluted protein peaks on the Profinia instrument. Automatic peak detection includes
several parameters that may be changed from the default settings, depending on the
method:
• Peak detect delay — at the start of the elution step, the automatic peak detection
algorithm is activated after a set time delay. The programmed default setting for peak
detect delay is based on the fluidics of the Profinia instrument and is optimized for
Bio-Rad methods. After the specified peak detect delay, the Profinia instrument starts
actively monitoring for the expected affinity or desalting peak, and a light bulb icon
displays on the screen immediately in front of the UV cartridge line. Following peak
detection, the method proceeds to the next step and the light bulb icon disappears. The
peak detect delay parameter is intended to prevent premature activation of the automatic
peak detection algorithm, which could be caused by late eluting contaminants on wash 2
steps.
• Max peak volume — maximum volume the system pumps before overriding automatic
peak detection. Once this volume is reached and a peak was not detected, the method
proceeds to the next step. The programmed default setting for max peak volume is
based on the fluidics of the Profinia instrument and is optimized for Bio-Rad methods.
The max peak volume parameter is intended to prevent loss of sample in the event the
automatic peak detection algorithm does not recognize a peak during the specified time
window
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