# K171770: cobas Cdiff Nucleic acid test for use on the cobas Liat System

- Pathway: 510(k) (Traditional)
- Applicant: Roche Molecular Systems, Inc.
- Decided: Sep 12, 2017 after 90 days
- Product code: OZN (C. Difficile Toxin Gene Amplification Assay)
- Device class: 2
- Regulation: 21 CFR 866.3130
- Recalls of this device: none
- Data: FDA decisions to Oct 25, 2026; recalls to Oct 12, 2026

## Lineage
Longest line of descent: 4 generations back to K923463 (1993). 5 ancestors in all.
4 later devices descend from it; 2 cite it directly.
0 of 10 devices in its family (counting itself) have a Class I recall.

## Predicates on the family tree (from the FDA summary)
- K142422: cobas Cdiff Test, Roche Molecular Systems, Inc. (2015) Summary page 7.

## Most influential descendants
- K212427: cobas Cdiff nucleic acid test for use on the cobas Liat System (2021), 2 descendants of its own
- K260045: cobas® Cdiff Nucleic acid test for use on the cobas® Liat® System (07454945190); cobas® Cdiff Positive and Negative Control Kit for use on the cobas® Liat® System (07454970190) (2026), 0 descendants of its own
- K243730: Xpert C. difficile/Epi (2025), 0 descendants of its own
- K210385: cobas Cdiff nucleic acid test for use on the cobas Liat System (2021), 0 descendants of its own

## Indications for use
The cobas® Cdiff Nucleic acid test for use on the cobas® Liat® System is an automated, qualitative in vitro diagnostic test, that utilizes real-time polymerase chain reaction (PCR), for the detection of the toxin B (tcdB) gene of toxigenic Clostridium difficile in unformed (liquid or soft) stool specimens obtained from patients suspected of having C. difficile infection (CDI). The cobas® Cdiff Nucleic acid test for use on the cobas® Liat® System is intended for use as an aid in the diagnosis of CDI in humans in conjunction with clinical and epidemiological risk factors.

Source page: https://510kreport.com/device/K171770
Methodology: https://510kreport.com/methodology