Lyophilizer Protocol

1. Getting liquid nitrogen.  The sample will be frozen in liquid nitrogen.  To get the liquid nitrogen, go to the NMR room (FH 106).  In the room, there will be a big cylinder with the word nitrogen on the top.  Put the copper tubing onto the spout marked liquid.  Turn the valve on until you hear something coming out.  First there will just be gas, which is okay; it is just cooling the pipe.  Hold the blue bucket with the dewar inside under the copper tubing.  You may want to wear the face protector when doing this because the liquid nitrogen does spray out of the dewar occasionally.  When you have enough liquid nitrogen turn off the valve with a glove, because the valve will be cold.  Leave the copper tubing in the spout for now.  It is too cold to take off right now.

2. Freezing the sample.  Unscrew the lid of the test tube just enough that it can be moved around.  Drop the test tube into the liquid nitrogen and place the lid on top of the dewar.  The liquid nitrogen is boiling, but that is because the liquid nitrogen is so cold and the test tubes are room temperature.  Once the liquid nitrogen stops fizzing then the sample is probably frozen all the way.  It is okay to leave the test tube in the liquid nitrogen if you don’t think that they are frozen all the way through. 

3. Preparing the lyophilizer.  Turn on the lyophilizer and press the button marked “Auto”.  This will automatically set the temperature, when it reaches the appropriate temp the vacuum will automatically turn on, so make sure all the valves are closed otherwise the small little vacuum will try to set the whole room/hall/building to vacuum.  Keep an eye on the two progressions of lights on the front of the console.  When they both reach green all is well and you can move on.  While waiting for the lights, place a folded paper towel into the bottom of the glass container. 

4. Preparing the sample.  Take the sample out of the liquid nitrogen.  You may use gloves or tongs to take it out.  Remove the cap quickly and place a kimwipe on top of the tube and wrap a twist-tie around the test tube to keep the kimwipe in place.  Drop the test tube and lid into the glass container.  Repeat for any additional test tubes.

5. Putting the sample on the lyophilizer. Take the glass container to the lyophilizer and put the glass container top on the glass container.   Put the top on to an appendage and turn the gray knob at the end of the appendage to turn on the vacuum.  Watch the lyophilizer until the vacuum has been reached (the vacuum light has reached green).  The sample will stay on the lyophilizer until the sample is dry.  One way to tell if the sample is done is to close the appendage valve to bring the sample back to room pressure (see below).  Pick up the sample if it is still cold to the touch it is not done yet put it back under vacuum as before.  If it is not cold to the touch it should be done.

6. Taking the sample off of the lyophilizer.  Turn the grey knob the other way to release the vacuum.  Remove the glass container from the lyophilizer.  Take off the kimwipe and twist-tie and screw the cap back on the test tube.  Your sample is ready.