Construction of graduated drinking tubes
There
are five components, four to make the tubes, and one for the cage:
Seal between the sipper tube and reservoir
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
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
Figure
Figure 1. A drinking tube assembled (left)
and its components (right)
