(486 days)
This assay is designed to provide a method for the detection and quantification of chromosome 8 in both interphase nuclei and metaphase spreads by fluorescence in situ hybridization (FISH).
The CEP 8 SpectrumOrange DNA Probe is a SpectrumOrange fluorescent labeled DNA probe specific for the centromeric region of chromosome 8.
Here's a breakdown of the acceptance criteria and the study that proves the device meets them, based on the provided text:
Acceptance Criteria and Device Performance for CEP 8 SpectrumOrange DNA Probe Kit
1. Table of Acceptance Criteria and Reported Device Performance
| Performance Metric | Acceptance Criteria (Implicit) | Reported Device Performance |
|---|---|---|
| Analytical Sensitivity & Specificity | ||
| Hybridization Failure Rate | =2 tri-signaled metaphases for metaphase). The sensitivity, specificity, and correlation coefficients reported are for the device's performance when applied according to its instructions. |
7. Type of Ground Truth Used
- For the clinical methods comparison study, the ground truth was expert consensus / established diagnostic method: Standard Cytogenetic Analysis. This method is referred to as "the standard of care."
8. Sample Size for the Training Set
- The text does not explicitly describe a separate training set in the way modern machine learning models would have one.
- The "pilot study" and "pivotal study" results for hybridization efficiency and reproducibility involve smaller numbers of specimens (35 BM, 60 BM, single normal and single trisomy 8 specimens) that could be considered part of the development and refinement of the assay and its interpretation rules, but not a formal "training set" for an algorithm. The 2.2% cutoff for interphase analysis appears to have been 'validated by the same pivotal clinical study,' suggesting it was developed and then verified within the context of the overall validation.
9. How the Ground Truth for the Training Set Was Established
- Since there's no explicitly defined "training set" for an algorithm in the modern sense, the concept of establishing ground truth for it doesn't directly apply here.
- However, the underlying biological understanding and the methodology of interpreting FISH signals (e.g., what constitutes a "tri-signaled nuclei") would be based on established cytogenetic principles and likely refined through internal studies during the probe's development, informed by standard cytogenetic analysis, which is the gold standard for chromosomal abnormalities. The cutoff values (like 2.2%) were likely empirically determined and then validated against the clinical performance.
§ 866.4700 Automated fluorescence
in situ hybridization (FISH) enumeration systems.(a)
Identification. An automated FISH enumeration system is a device that consists of an automated scanning microscope, image analysis system, and customized software applications for FISH assays. This device is intended for in vitro diagnostic use with FISH assays as an aid in the detection, counting and classification of cells based on recognition of cellular color, size, and shape, and in the detection and enumeration of FISH signals in interphase nuclei of formalin-fixed, paraffin-embedded human tissue specimens.(b)
Classification. Class II (special controls). The special control is FDA's guidance document entitled “Class II Special Controls Guidance Document: Automated Fluorescencein situ Hybridization (FISH) Enumeration Systems.” See § 866.1(e) for the availability of this guidance document.