Ting's Ice Set-up for Fly Work

A "how to" guide

 

Microscope

 

The microscope must be able to accommodate the height of the ice stage.  A Wu Lab microscope:

 



 

Chilling Box

1. Styrofoam box bottom, lined with small plastic bag to prevent the styrofoam from becoming water-logged.  Beach coolers make great boxes.

 



 

2.  Styrofoam box top (used upside down) with four holes, each filled with a glass shell vial.  The vials are held in place by two sets of rubber bands that keep them from sliding out in either direction.  Without the rubber bands, the vials will not stay in place.  See the underside of the box top:

 



 

3.   "Chilling vials" with a Kimwipe stopper are placed into the four glass shell vials.  Flies go into these chilling vials.

 

4.  To assemble for fly work:  First, put ice in the styrofoam box.  Second, add water to make an icy slush to within 1.5 inches of the rim.  Third, place the styrofoam top on the box so that the shell vials sit in the icy slush.

 

 

Ice Stage

 

1.  Components:

    White plastic jar with a round piece of styrofoam inside to help the ice float. Blue insulating foam with two rubber bands:

 

 

Progresso soup can to form the ice:



 

2.  To assemble for fly work:

    A.  Fill the Progresso soup can to about 2/3 full.  Let freeze at -20 degrees.

    B.  When the ice has formed, remove the ice by running hot water around the can and sliding the ice out.

    C.  Fill the plastic jar with water.

    D.  Put the ice into the plastic jar, on top of the styrofoam floater.  Make sure that the ice is floating freely from the sides of the jar.

    E.  Put the cap on the jar.  Do this over the sink, as water will be running out as the ice gets pushed further down.

F. Place the plastic jar inside the blue insulating foam, for a longer lasting ice stage.

 



 

 

Using the ice setup

 

Once the chilling box and ice stage are set-up (which takes about 2 minutes and lasts for about 5 hours), you are ready to chill flies.

1.  Transfer flies from the vial they are in into your chilling vial.  Tap against a place mat to prevent breaking the glass chilling vial.  The chilling vial should be pre-chilled to prevent flies from easily crawling up the sides.  Also, long forceps and a kimwipe can be used to wipe off any condensation before adding flies, so that they will not get trapped in the moisture.  The flies will become immobile within seconds.

2.  If flies are in a bottle, use a funnel to get them into the chilling vial.  This funnel should have the plastic ridges on the outside razored off, so as not to cause the chilling vial to shatter with the force of repeated tapping.

3.  After flies are chilled, pour them onto the ice stage.  The flies will remain immobile and allow you to do microscope work as long as the ice stage remains cold.

4.  To remove flies from the ice stage, brush them onto an index card folded lengthwise.

5.  One of the four slots in the ice stage can be used for a morgue vial to collect the discarded flies.  This vial can be put in the freezer at the end of the day to kill the flies...make sure not to leave this sitting behind overnight, as the ice will melt by morning and the flies will wake up and escape.

 

Additional notes

1.  To minimize condensation during warm summer months, a white index card cut to the shape of the ice stage can be placed on top of the stage and used as a sorting surface.

2.  There are no obvious side effects to chilling the flies.  They wake up within seconds after being removed from the cold stage.  Chilling does not virginize female flies or sterilize male flies.