Accurately counting the number of colony-forming units (CFU) on an agar plate forms the basis of quality control microbiology testing for pharmaceutical, cosmetic, food and environmental industries. Traditionally, colony counts were performed manually but this method is time-consuming, and can lead to issues with results, such as technician to technician variability and human error, not to mention eye strain. Another downside of manual counting is the lack of traceability after plates have been discarded, which can lead to issues down the line during root cause analysis investigations.
Why switch to an automated colony counter?
In order to standardise count results and improve traceability, many labs are now moving towards automated and semi-automated colony counters. These systems not only speed up testing but create a comparable trend of results that eliminates human error and variability.
There has also been a push towards ‘lean laboratory’ initiatives in recent times, which aim to improve throughput and productivity by focusing on value-added activities and reducing any wasteful processes in the lab. One of the easiest areas to streamline is colony counting, since automated colony counters can analyse up to 75 plates in 5 minutes. This can free up a large portion of time for laboratory analysts to spend on more ‘value-added’ tasks and projects.
Benefits of automated colony counters
- Saves time
- Increases sample throughput
- Improves accuracy
- Standardises results
- Eliminates human error
- Increases sensitivity to smaller colonies
- Automatic data transfer to database / LIMS
- Stores images and count data for traceability
- Full audit trail and report generation (PDF / Excel)
- Can link to barcode readers to eliminate data input errors
How to switch to an automated colony counter?
Before you incorporate an automated colony counter into your laboratory, it is important to carry out a validation study to ensure that the new system is accurate and comparable to manual counts performed by an experienced microbiologist. Many automated colony counters can be purchased with IQOQ documentation, making it easier to qualify the system before carrying out your individual validation studies.
Your validation procedure should include analysis of multiple plate types that are typically tested in your lab. It is important to analyse colonies of various shapes, sizes, and colours to ensure that the programmes you set up within the software will successfully detect your organisms of interest. Once you have shown that there are no statistically significant differences between the automated colony count results and your verified manual colony counts, you can start to incorporate your automated colony counter into day-to-day testing.
|Manual Counting||Automated Counting|
|Slow process||Rapid Process|
|High risk of human error||Removes risk of human error|
|Variability between technicians||No variability between technicians|
|Limits throughput||Increases throughput|
|Relies on eyesight||Uses HD scientific-grade camera|
|No traceability or images of plates||Plate images and count data stored|
|Requires manual input to LIMS||Can automatically transfer data to LIMS|
|Reports need to be made using LIMS||Produces professional reports|
|Lack of traceability||Full audit trail and CFR 21 Part 11 compliance|
MSC offer the widest range of colony counters to suit a range of applications:
- aCOLade 2 – Manual colony counter
- aCOLyte 3 HD – Basic semi-automated colony counter
- Protos 3 – Automated colony counter and Chromogenic ID system for universities, food, water, and environmental laboratories.
- ProtoCOL 3 – Automated colony counter with full traceability and CFR 21 Part 11 compliance for pharmaceutical, cosmetic, and other highly-regulated laboratories.
- AutoCOL – Fully automated, robotic, walk-away colony counting system
If you would like more information on the Synbiosis colony counter range, contact MSC below: