Validation and Implementation of the Roche FLOW System in a Large Routine Molecular Diagnostic Laboratory

Background - The PHE Public Health Laboratory, Birmingham at Heartlands hospital has an annual turn-over in excess of 750,000 specimens, 41,000 of which are processed using real-time PCR in the molecular section. In 2017, due to the age of existing instrumentation, the laboratory began a programme of replacement.

Methods - During 2017-19 the entire molecular service was replaced with a new high-throughput automated Roche FLOW system, consisting of a primary sample handler (PSU), two MagNA Pure 96 instruments, a PCR set-up unit (PSU), three 384-well LightCycler 480 II instruments and overarching FLOW software responsible for automated data handling, specimen tracking and workflow between the instruments.

Results - The bulk of the in-house developed assay repertoire, representing 34 viral, bacterial and fungal targets was re-optimised in 19 multiplexes. These were fully validated against existing molecular tests and were introduced into routine diagnostic service in June 2018. The FLOW software was successfully interfaced with the LIMS system, allowing rapid two-way communication of test requests and results. Over the following ten months, the service was expanded with an additional seven targets. The new system and assays were audited by UKAS in April 2019 and achieved accreditation to ISO:15189:2012 in August 2019.

Conclusion – The Roche FLOW system was successfully validated and introduced into routine diagnostic service and now offers significant improvements in assay performance, sample throughput and turnaround time. Details of the validation process, post-implementation modifications, trouble-shooting and lessons learnt will be of value to other diagnostic laboratories considering the introduction of this technology.