Making Sample Quality Visible
A new solution to this challenge uses high-resolution vision technology to audit both volume and precipitate in racks containing up to 96 tubes. An advantage of this approach is that auditing can take place without de-capping of the tube, thus minimizing any exposure of the sample and helping reduce potential degradation or cross-contamination.
A high-speed vision system incorporated into a benchtop instrument is used to image multiple sample tubes simultaneously—up to a full column of eight tubes in a standard SBS footprint rack. The captured image is analyzed, and the liquid meniscus detected for each tube being audited.
Advanced image processing routines take into account variations between different liquid types, for example DMSO or aqueous solutions.
Once the position of the meniscus has been determined, the volume of liquid is calculated, taking into account the tube type. Further algorithms are used to detect the presence of a cap and any precipitate in the base of the tube.
Figure 1 illustrates a column of eight tubes following image capture, with various regions of interest depicted, with detection of caps, meniscus, and precipitate (in two of the tubes).
Benefits of this approach include: speed, less than two minutes to audit a 96 tube rack; accurate, volume measurement better than +/-10 µL; precipitate and cap detection; no need for tare-weighing of tubes; noncontact and operates with capped tubes.