# Performance evaluation of the Cobas c 703 analytical unit as part of Cobas Pro integrated solutions using LED as the sole photometric light source

## TL;DR

This study compares the performance of a new LED-based clinical chemistry system with older halogen-based systems and finds them equally effective.

## Contribution

The study demonstrates that LED-based systems can replace halogen-based systems without compromising analytical performance.

## Key findings

- The c 703 analytical unit showed robust precision with most coefficients of variation below 1%.
- LED-based c 703 showed good comparability with halogen-based c 701/c 702 modules.
- The c 703 analytical unit has a longer-lasting LED light source (10,000 hours) compared to halogen lamps.

## Abstract

Most commercially available clinical chemistry systems today rely on a halogen light source to power photometric measurements, lasting only up to ∼750 h before replacement is required. Halogen lamps will soon be phased out in favor of new longer-lasting light-emitting diodes (LED) in commercial devices.

We compared the analytical performance of the new Cobas® c 703 analytical unit (LED; Cobas Pro integrated solutions) versus the Cobas c 701/c 702 modules (halogen light source; Cobas 8000 modular analyzer series; all Roche Diagnostics International Ltd). At two evaluation sites, precision of the c 703 analytical unit was evaluated and method comparison experiments comparing the c 703 analytical unit versus c 701/c 702 modules were performed.

Results from 34 selected applications showed robust precision of the c 703 analytical unit (repeatability, intermediate precision, and reproducibility: 80/138 coefficients of variation <1 %, 60/138 < 1 %, and 48/69 < 2 %, respectively). Method comparison experiments with 31 applications showed good comparability between c 703 and c 701/c 702 using LED versus halogen light sources, respectively (median slope = 1.00; median bias = 0.2 %; median Pearson's correlation coefficient = 0.997).

In addition to the newly introduced LED light source having a longer lifetime (10,000 h; data not shown), the c 703 analytical unit demonstrated equivalent analytical performance to that of the c 701/c 702 modules using halogen lamps as the light source as part of high-throughput clinical chemistry analyzers.

•This study compared Cobas® c 703 using LED vs Cobas c 701/c 702 using halogen lamps.•LED have been shown to last longer than halogen as a light source.•The c 703 analytical unit using LED demonstrated robust precision.•Good comparability was observed between analytical units/light sources.•c 703 shows equivalent analytical performance vs c 701/c 702.

This study compared Cobas® c 703 using LED vs Cobas c 701/c 702 using halogen lamps.

LED have been shown to last longer than halogen as a light source.

The c 703 analytical unit using LED demonstrated robust precision.

Good comparability was observed between analytical units/light sources.

c 703 shows equivalent analytical performance vs c 701/c 702.