Evaluation of an automated liquid-handling system (Tecan Genesis RSP 100) in the Abbott LCx assay for Chlamydia trachomatis

Abstract

The present study investigated the feasibility of automating the specimen-pipetting component of sample preparation in the LCx Chlamydia assay (LCx-CT assay; Abbott Laboratories, Chicago, Ill.) by using a commercially available liquid-handling system (Tecan Genesis RSP100; Tecan Inc., Research Triangle Park, N.C.). The Tecan instrument proved to be comparable in both precision and accuracy to a manual multipipettor (Eppendorf model 4850; Eppendorf Scientific, Westbury, N.Y.). The Tecan instrument was extensively checked for evidence of specimen-to-specimen transfer, and no level of contamination sufficient to generate a signal above the background in the LCx-CT assay was detected. Finally, pipetting speed was significantly improved by using the Tecan instrument. A mean time of 2.5 min was required to pipette a complete LCx-CT assay carousel (20 samples and 4 controls) with the Tecan instrument, whereas 8.4 min was required to pipette a comparable number of samples manually (P < 0.001).

FIG. 1

Typical daily LCx assay workflow at HCMC enables analysis of a maximum of 120 samples tested for both C. trachomatis and N. gonorrhoeae in an 8-h shift by one technologist using four thermocyclers and four LCx analyzers. a, each run consists of 40 samples (80 tests) plus controls; b, completion of run 3 from the previous day; c, results reporting and instrument cleanup. The following assay procedures are represented by the indicated symbols: sample preparation, solid gray bars; sample transfer to amplification vials, open bars; thermocycler loading, solid black bars; amplification, dotted bars; LCx analyzer loading, vertically hatched bars; product detection, diagonally hatched bars.