Automation and software helps microbiology lab

The project, carried out at Westwards Microbiology Laboratory by Kiestra Lab Automation of the Netherlands and LIMS specialist Autoscribe UK, has allowed the lab to process more samples in a shorter time window, creating a substantial increase in efficiency and throughput.

Westward's microbiology laboratory processes hundreds of samples each day for microbiological analyses so there was a pressing need for a system which would not only automate the actual testing process but also track and trace the samples and associated results.

The key to this real-time automation was real time barcode labelling of all sample carriers (such as bags, tubes, dishes, bottles) provided by Kiestra's BarcodA system. This was used in conjunction with Autoscribe's Matrix LIMS. Real time barcode reading is known to reduce transcription error rates to only 1 in 36 trillion characters - compared to 1 in 300 characters with manual reading.

Kiestra's BarcodA automatically places an optical barcode on all tubes, bottles and petri-dishes that contains important information such as composition, sell-by date etc. The barcode makes every sample carrier unique and recorded meaning full traceability for the laboratory. Samples are also provided with a barcode which is generated by Matrix LIMS.

On the automation side, the first step of each sample's preparation is dilution, and at the Wastwards labs this was performed by Kiestra's gravimetric dilutor, the SynergA, connected to a PC via the Dutch firm's TraceA software which allows full traceability of all dilution operations.

In full automatic mode, the sample barcode includes information about the type of dilution required , and when the sample barcode is scanned, the system automatically checks to see if the starting weight is within the predefined limits, selects the bottle of media to be used, makes the dilution and checks if the accuracy is correct.

The TraceA software package makes sure that all relevant data is stored automatically (date, time, analyst id, sample id, weight of sample, media batch number, weight added, and media). This data is then automatically exported to the Matrix LIMS.

At the next stage - testing - every sample in a Petri dish is labeled using the BarcodA system at a speed of 1000 dishes per hour. Sample barcodes were scanned at the pipetting bench with a barcode scanner. Autoscribe LIMS then sent the tests associated with the particular sample to BarcodA so that the Petri dishes can be labelled with a barcode specific for each test. The technician then instantly receives the right set of test plates per sample.

After pipetting the sample into the Petri dishes and assignment of the associated tests, the Kiestra AgarrA module comes into action. AgarrA is used for automatic agar pouring, mixing, solidifying and stacking. This system automatically scans the barcode on each dish and pours the plate with the correct molten media for the test, after which mixing, solidifying, and stacking takes place. AgarrA enables users to save 30 per cent of agar costs each day, thanks to the precise dosing system, according to the comapnies.

Matrix LIMS receives all the relevant data from BarcodA and AgarrA, in order to keep track of the whole history per sample to an individual dish level.

During the whole process, an automatic check is also made at each step to determine if all required samples have passed the required step before proceeding to the next step. This ensures that all the necessary steps in the process are completed. Based upon this principle Westward Labs can generate complete daily audit trails for every sample.