Written and maintained by CASRAI Editorial Board
Published · Last updated
On this page
General product and regulatory information only. This page is not medical advice and does not describe how any procedure is performed.
Short answer
An endoscopic cytology brush is a brush on a shaft that is passed through an endoscope so that cells can be collected for cytological evaluation. In the FDA product classification database it is product code FDX, device class 2, under 21 CFR 876.1500 (“Endoscope and accessories”). It is a different device from the brush used to clean an endoscope, which that same regulation lists as Class I.
Definition and scope
The FDA record for product code FDX is titled “Endoscopic Cytology Brush” and gives its definition in one line: “To collect cells for cytological evaluation.” Its review panel is Gastroenterology and Urology, and the record describes the physical state as a brush and shaft with a target area of various tissues in the gastrointestinal and genitourinary tracts. This page covers that device. Brushes sold for other purposes or sample sites carry their own FDA records and are outside its scope.
The regulation itself names the device. 21 CFR 876.1500(a) describes an endoscope and accessories as a device used to provide access, illumination, and allow observation or manipulation of body cavities, hollow organs, and canals, and its list of examples includes “cytology brushes for endoscopes” as well as “cleaning accessories for endoscopes.” The two appear side by side in the same sentence, which is one reason they get confused.
How it is used in practice
The FDA record summarises the technical method in a single sentence: the brush is used through the endoscope to collect cells. The collected cells go to cytological evaluation, which is the pathology step described in what pathology is. Clinical technique, channel compatibility and handling steps are set by the manufacturer’s instructions for use and by the clinician. For background on the instrument the brush travels through, see what an endoscope is, and for how the endoscope itself is processed between uses, endoscope reprocessing.
Cytology brush versus endoscope cleaning brush
Both devices are brushes, both are used with endoscopes, and both are discussed in 21 CFR 876.1500. They are classified separately, and the difference is the practical information gain of this page. The table draws on the FDA product classification record for FDX, the openFDA classification data and the text of the regulation.
| Point of comparison | Endoscopic cytology brush | Cleaning brush for endoscope |
|---|---|---|
| Named in 876.1500(a) as | “cytology brushes for endoscopes” | “cleaning accessories for endoscopes” |
| Stated purpose in FDA records | “To collect cells for cytological evaluation” (product code FDX) | Listed as a cleaning accessory for endoscopes |
| Classification | Class 2 (product code FDX) | Class I, listed in 876.1500(b)(2) as “cleaning brush for endoscope” |
| Premarket notification | The (b)(1) list of Class II exempt devices does not name a cytology brush, and the FDX record shows GMP exempt as “No” | Exempt from premarket notification, subject to the limitations in 876.9 |
Do not read the exemption in the right-hand column across to the left-hand column. The regulation text names the cleaning brush in its Class I exemption paragraph; it does not do so for the cytology brush.
Where it matters for labs, clinics and supply decisions
Three details from the public FDA data are useful when a catalogue entry or a product listing needs checking.
- The product code is a grouping, not a single product type. The openFDA 510(k) data lists 44 records under FDX (data last updated 2026-10-19). Their device names include “CYTOLOGY BRUSH” (K914504), “HOBBS MEDICAL MICROBIOLOGY BRUSH” (K893729) and “GASTROINTESTINAL SHEATH BRUSH” (K834402), and also “LAPAROSCOPIC CLEANING BRUSH INSTRUMENT” (K911481). A name containing “brush” therefore does not on its own show that the device is a cell-collection brush; the cleared indication of the specific device is what counts.
- The class and regulation are looked up, not assumed. The FDX record gives Class 2 and regulation number 876.1500. The FDA classification database is searchable by product code, so a listing that quotes FDX, Class 2 or 876.1500 can be compared against the FDA record directly.
- Single-use or reusable status is a labeling question. The FDA classification record for FDX does not state it. It is set out in the individual manufacturer’s instructions for use. For reprocessing rules that apply to reusable devices in general, see medical device reprocessing.
For the wider clearance picture, the 510(k) guide explains what the K-numbers above are, and the endoscopy center supply checklist shows where a cytology brush sits among other endoscopy consumables.
Common misunderstandings
- “A brush used with an endoscope is a cleaning brush.” Only one of the two is a specimen-collection device. FDA lists the endoscope cleaning brush as Class I and the endoscopic cytology brush under FDX as Class 2.
- “Everything under 876.1500 is Class I or exempt.” The regulation has separate Class II and Class I paragraphs, and the exemptions apply only to the devices each paragraph names.
- “The product code tells you exactly what the device is.” As the FDX records show, one code can hold several brush types. Read the device name and indication on the specific record.
Frequently asked questions
What is a cytology brush?
An endoscopic cytology brush is a brush on a shaft that FDA describes as a device “to collect cells for cytological evaluation.”
What FDA class and product code does it have?
Class 2, product code FDX, under 21 CFR 876.1500.
Is a cytology brush the same as an endoscope cleaning brush?
No. The regulation lists “cleaning brush for endoscope” in its Class I paragraph, while the cytology brush is classified separately as Class 2 under FDX.
Sources
- U.S. FDA, Product Classification database, product code FDX, “Endoscopic Cytology Brush”: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpcd/classification.cfm?id=FDX (checked 2026-10-30).
- openFDA device classification and 510(k) endpoints, product code FDX: https://api.fda.gov/device/classification.json?search=product_code:FDX and https://api.fda.gov/device/510k.json?search=product_code:FDX (data last updated 2026-10-19; checked 2026-10-30).
- 21 CFR 876.1500, Endoscope and accessories: https://www.law.cornell.edu/cfr/text/21/876.1500 (checked 2026-10-30).
