How to Reprocess the MAJ-855 Water Tube and the GI Endoscope’s Auxiliary Water Channel

This article by Lawrence F Muscarella, PhD, is to be read in conjunction with the comprehensive article entitled “Recommendations to Prevent Healthcare-Acquired Infections,” which is referred to below as the “main article” and can be downloaded in PDF format by clicking here.


As much as any other lesson, the reprocessing breaches identified at the three Veterans Administration Medical Centers (VAMCs) in Murfreesboro (TN), Augusta (FL), and Miami (FL) (refer Dr. Muscarella’s related article “Improper Use and Reprocessing of a Gastrointestinal Endoscope’s Auxiliary Water System” — click here) teach the importance of proper use and reprocessing of both the Olympus MAJ-855 auxiliary water tube and the colonoscope, including its auxiliary water channel.13,20

A diagram showing the MAJ-855 auxiliary water tube connected to the GI endoscope to flush water through its auxiliary water channel is provided in another of Dr. Muscarella’s articles entitled “Faulty Use of a GI Endoscope’s Auxiliary Water Channel”, which can be downloaded by clicking here.

The purpose of the MAJ-855 auxiliary water tube

The MAJ-855 auxiliary water tube has two purposes:27 

  • First, it may be used to supply the GI endoscope’s auxiliary water channel with (sterile) water for flushing the GI tract’s mucosa, which may be required to enhance visibility during the clinical exam.20 (Flushing may be achieved manually via a syringe or using an automated water pump.27
  • Second, the MAJ-855 tube may be used as an adapter to reprocess the GI endoscope’s auxiliary water channel.


The following recommendations provide guidance to reprocess the MAJ-855 auxiliary water tube and auxiliary water channel both manually and using an automated endoscope reprocessor (AER). (Refer to the operator’s manual of the GI endoscope for more detailed instructions.)

I. Initial quality-assurance verifications:

A. Verify whether any GI endoscopes in inventory feature an auxiliary water channel that uses a MAJ-855 tube for flushing (i.e., Olympus 160 and 180 series: 3 models of gastroscopes, 13 models of colonoscopes).20

B. Confirm that the MAJ-855 water tube and the GI endoscope’s auxiliary water channel are both being reprocessed after each clinical case, in accordance with their manufacturer’s instructions.20

Caution: If it was connected to the GI endoscope’s auxiliary water channel during the clinical case, the MAJ-855 auxiliary tube requires reprocessing, regardless of whether this channel (and tube) was used or flushed with water.20

C. Prior to GI endoscopy, visually verify that the MAJ-855 tube is fitted with the correct green, double-winged (one-way flow) valve (with which the MAJ-855 tube was originally manufactured and shipped).13,20

Caution #1: Do not remove this green, double-winged valve from the MAJ-855 tube. This valve is crucial to the MAJ-855 tube’s safe and effective use.13,20

Caution #2: Do not use the MAJ-855 tube if it is fitted with a similarly-shaped, green, single-winged (two-way flow) connector, which is intended for use only with the Olympus MH-974 washing tube. Use of the MAJ-855 tube fitted with the MH-974 tube’s single-winged connector is contraindicated.13,20

II. Manual reprocessing of the MAJ-855 tube and the auxiliary water channel using a syringe:

A. Use a (30 ml) syringe to clean and high-level disinfect (and water rinse and forced-air dry), manually and simultaneously, the MAJ-855 tube and the GI endoscope’s auxiliary water channel (to which this tube is connected; see: main article) in accordance with the GI endoscope manufacturer’s instructions.13,20

Note: The manufacturer’s procedure and set-up for manually reprocessing the auxiliary water channel via the MAJ-855 tube are similar to those of the same manufacturer for manually flushing this channel with water during the exam via the MAJ-855 tube. 

III. Automated reprocessing of the MAJ-855 tube and the auxiliary water channel using an AER:

A. Some manufacturers suggest that their AER model(s) may be used to reprocess:

  • the auxiliary water channel via (and while simultaneously reprocessing) the MAJ-855 tube; and/or
  • the MAJ-855 tube by itself (i.e., while not connected to the GI endoscope).

Caution #1: The use of an AER to reprocess the MAJ-855 tube, whether connected to the GI endoscope’s auxiliary water channel or by itself, however, is ordinarily not recommended (see: Section III. C, below).

Caution #2: The MAJ-855 tube’s restrictive one-way valve, though of importance during the exam, can hinder the flow of reprocessing fluids through this tube’s lumen, limiting the AER’s effectiveness for reprocessing the MAJ-855 tube and, if it is connected to the GI endoscope, the auxiliary water channel.

B. Other manufacturers, however, may recommend that their AER model(s) be used to reprocess the GI endoscope’s auxiliary water channel via a different adapter—known as the (Olympus) MH-974 washing tube (or its equivalent)—while the MAJ-855 tube is reprocessed by itself (manually or using an AER).27

Caution: The MH-974 tube is fitted with a green, single-winged, two-way connector. Do not confuse this connector, or use it interchangeably, with the MAJ-855 tube’s double-winged, one-way valve (see: Section I.C, above).13,20,27

Note #1: According to its manufacturer, the MAJ-855 tube can be manually reprocessed by itself, either using a syringe to achieve high-level disinfection or a steam autoclave, or using an AER. (Steam sterilization of the MAJ-855 tube may require the purchase of additional tubes to maintain an adequate inventory.)

Note #2: Shorter in length (10 in.) than the MAJ-855 tube (4 ft.), the MH-974 washing tube features a connector that does not impede fluid flow and facilitates the AER’s connection to the auxiliary water channel, as some manufacturers of AERs recommend.13,27

C. The following guidance is provided if the medical facility (e.g., its GI endoscopy unit) is considering to use an AER model to reprocess the MAJ-855 tube either while connected to the auxiliary water channel or by itself, separate from the GI endoscope:

a. Obtain from the AER manufacturer’s quality assurance department a statement confirming that it has performed the necessary validation and verification tests (e.g., microbiologic tests performed under worst-case simulated in-use conditions) demonstrating, per FDA regulations, that the AER model can reprocess (including water rinsing and air-purging) the MAJ-855 tube (with its restrictive one-way valve firmly in place).

b. Alternatively, obtain from the manufacturer a letter confirming that the FDA has granted its AER model a 510(k) clearance to reprocess the MAJ-855 tube.

– If such a statement or letter is obtained, clarify with the manufacturer whether its AER model can be used to reprocess the MAJ-855 tube connected to the auxiliary water channel, or only by itself, separate from the GI endoscope. (If by itself, clarify whether the AER can simultaneously reprocess two MAJ-855 tubes.)

– If such a statement or FDA clearance letter is not provided to the medical facility, then the manual reprocessing of the MAJ-855 tube is advised (after each clinical case; see: Section II, above), although the automated reprocessing of the auxiliary water channel (using an adapter other than the MAJ-855 tube, such as the MH-974 washing tube) would presumably be appropriate, unless otherwise indicated.

Note: Some manufacturers may claim that their AER model(s):

  • are validated for reprocessing the auxiliary water channel via the MAJ-855 tube;
  • can reprocess the MAJ-855 tube, but only by itself (i.e., not while connected to the GI endoscope’s auxiliary water channel) and one at a time (not two of them simultaneously in the same basin); or
  • cannot reprocess either the auxiliary water channel via the MAJ-855 tube or the MAJ-855 tube separately, by itself.  Medical facilities are advised to verify which of these scenarios applies to their AER model(s).

IV. Additional instructions:

After connecting the reprocessed (“patient-ready”) MAJ-855 tube to the GI endoscope, flush and … (continued.) —> Click here to download this entire document in PDF format, which continues this blog and includes these “additional instructions.”

References: Click here.

Article by: Lawrence F Muscarella PhD posted on 12-14-2012; updated 7-29-2014.

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This entry was posted in Auxiliary Water Channel, Colonoscopes, Disease Transmission, Disposable Irrigation Tubing, Gastrointestinal Endoscopy, GI Endoscopes, High-Level Disinfection, Infection Control, MAJ-855 Water Tube, Risk Management. Bookmark the permalink.

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