Microbiology 345: Using a gradient mixer

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Microbiology 345 Using a gradient mixer
A mixing chamber is attached to a rubber tube
whose outlet is clamped to the bottom of a test
tube. Pipette 6.2 mL of dilute solution into the
M chamber of the mixer while the valve is closed.
Slowly open the valve to allow the solution to
fill the connecting line between the two
chambers. There should be no bubbles in this line.
Add 5.0 mL of concentrated solution to the R
chamber. Note that we coloured our denser
solution with red dye to make the gradient more
visible.
Position the automatic mixer so the bottom of the
stirring rod is about 3 mm from the bottom of the
m chamber. Begin mixing, avoid violent agitation
but with sufficient vigour that good mixing will
occur. Open the valve and open the stopper on the
tubing. Check to see if the liquid flowing
through the m chamber is being mixed.