Colony Picker: Principle, Protocol, and Advantages 

Colony picking or selecting is the most crucial part of identifying microorganisms (mainly bacteria). It is defined as the method of choosing one pure colony to duplicate it to use in the future. Observing, selecting, and counting colonies after inoculation in any culture media are critical steps in the microbiology laboratory. 

Automated colony pickers are the equipment that helps pick the desired colony from a cluster of different colonies from any culture media without manual stress. Not only colony picking, but automatic colony pickers also help prepare the samples and handle culture plates like transferring from liquid broth and plating in the agar medium.

Protocol of Colony Picking

The protocol of the colony picking has the following steps:

1. Firstly, culture the desired microorganisms in an agar plate.
2. After that, pick the selected isolated colonies from the plate using instruments like inoculating loop , needle, or toothpick.
3. Then, inoculate the chosen colony in a new agar plate, liquid broth, or biochemical media for obtaining pure culture.
4. Lastly, let the newly inoculated plate incubate overnight under the necessary condition.
5. Store or perform any further tests as per the requirement of the experiment.

Principle of Automated Colony Picker

The software controls the automated colony picker, and robotic arms pick the selected colony from the plate. The software has an image recognition facility. The laboratory personnel feeds the image into the software, which is recognized by the software in an agar plate placed at the detection site. Afterwards, the robotic arm picks up the selected colony and transfers it onto solid media plates and broth tubes. It is the basic principle of automation in colony picking tasks. 

The software controls the automated colony picker, and robotic arms pick the selected colony from the plate. The software has an image recognition facility. The laboratory personnel feeds the image into the software, which is recognized by the software in an agar plate placed at the detection site. Afterwards, the robotic arm picks up the selected colony and transfers it onto solid media plates and broth tubes. It is the basic principle of automation in colony picking tasks. 

Pickolo by SciRobotics has the feature of picking the colony and plating it into agar media spirally. Similarly, PIXL by Singer instruments has the feature of selecting and choosing the colony from the agar plate and placing it into the multiwell plates. 

Advantages of Switching to Automated Colony Picker

Although manual colony picking looks easy, it requires much more precision because one should know all colony characteristics of the needed microorganisms. The process becomes tiresome and repetitive in the long run. An increase in the number of samples also makes the task time-consuming. So, the following are the list of advantages of an automated colony picker over manual colony picking:

• Although an automated colony picker takes more than an hour to complete the task, it reduces the manual work of the laboratory personnel that requires full attention to the menial but essential work.
• Similarly, automation in colony picking reduces the chance of human-made error drastically because automated colony picker has advanced software that provides optimum precision.
• It decreases the number of laboratory workers as a single person can operate the machine and perform other tasks simultaneously. The system requires only feeding the image into the software and placing the agar plate in the detection site. 
• It does not have a complete walk-away facility, but it also does not require full attention to the machines only. Checking the plates/tubes where the selected colonies are to be transferred from time to time is enough after feeding the image and placing the plates in the detection site.

Reasons to Switch to Automation

The following are the reasons to switch to automation for colony picking:

• The bacterial samples are increasing in your clinical laboratory, and diagnosis of the causative agents is proving to be complicated. 
• The research samples are large, and multiple isolates are being tested from an agar plate with various colonies.
• You want to decrease the errors in the colony picking due to lack of precision.
• There is a shortage of trained staff in your laboratory. 
• It will help if you require cost-effective upgrading of your laboratory.

References

• QPix Microbial Colony Pickers. Molecular Devices. Retrieved 24 June 2022, from https://www.moleculardevices.com/products/clone-screening/microbial-screening/qpix-400-series-microbial-colony-pickers.
• Colony Picker. LabCompare. Retrieved 24 June 2022, from https://www.labcompare.com/Pharmaceutical-Lab-Equipment/1330-Colony-Picker/.
• Colony picking in synthetic biology. Moleculardevices.com. (2021). Retrieved 24 June 2022, from https://www.moleculardevices.com/sites/default/files/en/assets/infographics/bpd/colony-picking-in-synthetic-biology.pdf.