ABI Cleaning and Maintenance, Sample Prep and Running Procedures
**Do NOT use the ABI without being trained by Carmen, Kristin, or Jenny!**
Gel Block and Fittings
- In the 310 software: “Window”, then “Manual Control”
- Syringe Home à “Execute” – this will raise the syringe pump mechanism, allowing you to unscrew and remove the syringe.
- Loosen and remove the three fittings, the buffer reservoir and the capillary from the gel block.
- Place the fittings in a beaker of DI water and sonicate for ½ hour.
- Gently pull the gel block out of the instrument.
- Rinse the channels of gel block with warm tap water by plugging some of the holes. Do this until all traces of polymer are washed from the gel block.
- Rinse with DI water and COMPLETELY dry with nitrogen.
- Place the gel block back in the instrument by gently pushing it until it pops/clicks/slides into place.
- After sonication, COMPLETELY dry the fittings with nitrogen.
Capillary
- Cut a new capillary (if necessary) using the smooth side of the capillary cutter.
- Use very gentle scoring and then pull apart.
- Mark where window is (11 cm from the end) with sharpie.
- Put capillary in fitting in gel block, make sure the end of the capillary is in the T cross-section and then tighten the fitting.
- Place capillary over window and make sure the sharpie mark lines up with the detection window, then remove the capillary from the instrument:
- Place capillary between foil and clamp with tweezers.
- Place flame on it until it turns red (capillary should be charred).
- Put acetone on a Kimwipe and wipe until all black residue has been removed.
- Place capillary back into the instrument and make sure the capillary window aligns with the detection window.
- Position the capillary so that the tip slightly below the electrode (~1mm) and use tape to secure the capillary’s position.
- In the 310 software, “Instrument”, then “Change Capillary”
- Reset the counter to zero.
Buffer, Water and Waste Vials
- Prepare 1X ABI buffer:
- Aliquot 2 - 700 µL portions of the 10X ABI buffer (located in cold room) into a 15 mL falcon tube.
- Add enough DI water to make 14 mL of 1X buffer.
- Label glass vials and fill one with 1X ABI buffer and the other with DI water up to the fill line.
- Place white and grey caps on the buffer and water vials:
- Make sure the cap is dry and the grey is flush with the white.
- Push “Tray” button on instrument.
- Place ABI buffer in 1 and water in 2.
- In 3 goes a 1.5 mL tube with the lid cut off and filled with DI water to approximately the same position as the buffer and water level….this is for waste.
- Pour buffer into the buffer reservoir and fill to the red line:
- Make sure the buffer is made fresh each time you use it:
- You must change buffer once a week.
- If things start going bad and you’re using the instrument a lot then change the buffer.
- Screw on buffer reservoir (has an O-ring to tighten onto) and make sure you can push down the buffer valve over the reservoir which indicates it’s open.
Filling the Gel Block with Polymer
- Remove POP4 polymer from cold room and allow it to reach room temp.
- Shake polymer well and let it sit for 5 minutes after shaken:
- The syringe is typically filled to around 600 µL.
- You’ll need ~100 µL to fill the gel block.
- Fill syringe with ~600 µL of polymer and draw up some air.
- Clean outside of syringe with water and a Kimwipe.
- Tap the syringe gently with your finger or against your palm until any bubbles come loose.
- Depress the syringe until there is one drop of polymer on the end of the syringe.
- Loosen fitting on capillary and screw in syringe.
- Depress syringe until the channels are filled with polymer.
- Tighten right fitting first (fitting with capillary).
- Tighten bottom fitting next.
- Tighten top left fitting last.
- If any air bubbles appear in the gel block, then tap in more polymer.
- Flip silver switch on syringe pump to the right.
- In the 310 software, select “Window” then “Status”:
- Black boxes indicate what you’re aiming for and green boxes are what the instrument is at.
- Select “Window” then “Manual Control”.
- If you tell the instrument to do something in manual control and it doesn’t do it, you need to exit the software and re-open it.
- Autosampler to position 3 à “execute”
- Autosampler up à “execute” – Until the capillary is submerged in the waste vial.
- Buffer valve open à “execute”
- Syringe down à “execute” – Start with 100, then 50, then 25, then 10, then 5, and then 1, until the pump has pushed enough polymer through to remove any bubbles.
- Buffer valve close à “execute”
- Syringe down à “execute” – Make sure it is set to and increment of 1; continue executing until you hear the pump stay on. This will force polymer through the empty capillary.
Autosampler Calibration
- In the 310 software, “Instrument”, then “Autosampler Calibration”:
- Press “Start”.
- Remove autosampler tray and waste tube (in #3).
- Press “Resume”.
- Position the capillary over the silver dot on the tray:
- To lower step size, hold down shift when hitting the key to which way you want to move
- Get as close as possible, but not touching.
- Press “Set”.
- Repeat for dot in back of tray.
- Place tray back in and click “Finish”
- Close instrument doors.
Running Samples
- In the 310 software, “Window”, then “Manual Control”:
- Temperature set to 60 à “execute”
- To prep samples for injection (you should always include a positive and a negative control, and it is recommended to run an allelic ladder with each set of samples):
- Prepare the master mix:
- 24.5 µL of HiDi formamide and 0.5 µL of size standard per sample.
- Use ROX for CoFiler or ProFiler kits
- Use LIZ for IdentiFiler, MiniFiler or YFiler kits
- Aliquot 24 µL of master mix into labeled ABI sample tubes.
- Pipette 1 µL of sample into the sample tubes.
- Place grey cap on, then twist it and push at the same time so the cap is level with the sample tube.
- Clean the grey caps by sonicating in DI water for 10 mins.
- Pulse vortex and centrifuge all samples.
- In the 310 software, “File”, “New”, “GeneScan Sample Sheet 48 tube”
- Type in the names of your samples in the order you want them injected.
- Select the correct number of dyes for your samples
- Use “4 dye” for CoFiler or ProFiler kits
- Use “5 dye” for IdentiFiler, MiniFiler or YFiler kits
- Save your sample sheet by selecting “File”, “Save As”
- Save in the “Sample Sheets” folder
- Name the file with your initials and the date.
- Press “Tray” on the instrument and load your samples into the appropriate place in the tray. Press “Tray” again to return the tray to its starting position.
- Select “File”, “New”, “GeneScan Injection List”
- In the drop down menu, look for the sample sheet you just saved.
- You shouldn’t have to change any of the run settings, except for the injection time perhaps (no more than 15s for an injection).
- Change the matrix to the one that is appropriate for your samples.
- 4 dye – select the matrix with the most recent date.
- 5 dye – “08ds33”
- Click “Run”.
- The software will show you the status and test the syringe for leaks.
- The current should be between 6-9 μA.
- If the current is too high, check buffers and capillary.
- Make sure the voltage is at 15 kV.
- Background noise should be <1000 RFU.
- If it’s not, then the issue is polymer related.
- The primer peaks should come out around 2500s.
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