Construction of graduated drinking tubes

 

There are five components, four to make the tubes, and one for the cage:

 

Sipper tube

Seal between the sipper tube and reservoir

Graduated Reservoir

Stopper

Protector

(see Illustration)

 

Sipper tube

Critical features

 

The sipper tube provides the link between the solution and the mouse tongue.  One end of the tube must make a watertight fit with a graduated fluid reservoir.  The other end must allow taste solution to be obtained by the mouse.  It must resist the chemical actions of taste solutions, including acids and salts.  It must also be able to withstand chewing, scratching, and gnawing.  In practice, the only available material to do this is stainless steel.

 

The size of the hole through which the mouse licks fluids is critical.  Differences in the diameter of this hole can influence licking rates and fluid intakes.  If the hole is too large, spillage increases.  If it is too small, the mouse has difficulty licking viscous fluids.  It is standard for this hole to be 1/8” in diameter.

 

Some laboratories use sipper tubes with larger holes but a stainless steel ball.  These have the advantage of reducing spillage but they are (a) more expensive, (b) difficult to clean, and (c) occasionally block.

Specifications

Length: At least 1.75” (45 mm)

Tube outer diameter 5/16” (7.94 mm)

Wall thickness .028” (0.71 mm)

Hole diameter (where mouse licks) 0.125” (3.175 mm)

What we use

We use sipper tubes manufactured Unifab

 

The 2.5” (63.5 mm) long stainless steel straight sipper tubes are fine for most needs (Cat. No. US-171-25).  However, a shorter tube is a little more efficient, and so we order tubes custom made to be 45 mm (1.75”) long.

 

Cost

 

Depends on the number ordered.  In lots of 1000, they cost about $1.25/sipper tube for the 2.5” long tubes; $1.31 for the custom-made 45 mm tubes.  Shipping time, about 3-4 weeks (Dec 1999 prices).

 

 

Seal between the sipper tube and reservoir

 

What we use

 

Silicone tubing

 

Inner diameter, 5/16” (tube with ID ¼ (6.4 mm) will also work but it is a tight fit over the sipper tubes, making assembly a strain).

Outer diameter, ½” (12.8 mm)

 

Cut into ½” lengths with a tube cutter, scissors or a sharp modeling knife.  A plastic tubing cutter (Bel-Art Products, cat no. 21010-0000; Pequannock, NJ 07440-1992) makes the job faster and gives a straighter cut.

 

Vendor and cost

 

Vendor Cole-Parmer, Cat. No. 06411-76 (best) or (less good) 06411-74

25 ft for $75 (enough for about 600 tubes)

 

Graduated Reservoir

 

Typical water  intakes of mice are ~5 ml/day.  Intakes of highly preferred solutions such as saccharin can be as high as 25 ml/day.  The goal here is to provide at least a day’s worth of fluid in a graduated container that can be easily read.  If the reservoir is too small it must be refilled frequently.  If it is too large, it can be either too wide in diameter to allow accurate measurements or too long to be conveniently held on the cage.  Extensive attempts to improve on our design has taught us that if the reservoir is too narrow, there is insufficient room for fluid to drain and air to rise to the top, leading to a blockage.

 

What we use

 

25-ml plastic serological pipettes, with gradations every 0.2 ml.

Fisher cat no. 13-678-14B

 

Stopper

 

What we use

 

Rubber stopper, size 00

Fisher cat no. 14-130A

 

Protector

 

If the mice can get hold of the silicone seal or plastic reservoir they will chew on them.  To prevent this, we install a guard on each cage.  This is a thin metal sheet with two holes drilled to accept the drinking spouts.  The holes also force the drinking tubes to be placed in the same place each time they are used.

 

What we use

 

A piece of sheet metal, approx 4” long, with two holes for the drinking spouts and two for nuts and bolts to mount it to the cage lid (see figure)

 

Alternative: A steel washer around each drinking spout.  These are fine for small experiments, but they are not as convenient as the metal strip protector because they do not stay in place

 

 

 

 

Note the metal strip that stops the mouse from eating the silicone seal

 

 

 

 

 

 

 

Manufacturers/Vendors

 

Unifab

Supplies for Sipper tubes

Contact for custom orders: Bob Boyington

 

5260 Lovers Lane

Lalamzoo, MI 49002

 

Phone: (800)-648-9569 or (616)-382-2803

Fax: (616)-382-2825

Cole Parmer

Supplies for tubing used for seal between sipper tube and reservoir

 

Fisher

            fishersci.com

 

 

Figure

 

Figure 1.  A drinking tube assembled (left)
and its components (right)