We have often been asked “Am I able to use the mmi CellCut plus and collect onto the Ampligrid” – we are happy to say that the answer now is yes. This means that the mmi combi system (mmi CellCut Plus with mmi CellEctor Plus) is the only microdissection system that guarantees 100% collection of single microdissected cells onto an Ampligrid for downstream single cell PCR. We were recently approached by a customer interested in purchasing an mmi combi system and asked this very question again so we began to work on it and were more than happy with the outcome. The sample used for this experiment consisted of mouth epithelial cells stained using an mmi H&E staining kit. The Ampligrid slide was placed in position 1 on the stage, the membrane slide for cutting was mounted in the usual way with a clean glass slide placed beneath it and then placed directly into slide position 2. A slide with a reservoir of 10% PBS buffer was placed in position 3. Before beginning the workflow both the mmi CellCut Plus and mmi CellEctor Plus were fully calibrated and the plane tilt and the 3D capillary position determined The mmi CellEctor Plus was equipped with a 40µm 45˚ capillary filled with buffer as shown in the manual and set in the scrapping position with a contact z position of -5µm. To start off the mmi CellCut Plus software was selected and the system was set up in the usual way. The only difference was since the cells were to be collected with the mmi CellEctor Plus then the caplift holder was not in place. The following workflow is still under development; however the basic process was straightforward and gave good reproducible results. This method currently still involves some manual manipulation steps but soon it will be fully automated. The basic workflow - Move to slide 2 and cut out the cells of interest using the freehand drawing tool – this can be done either with the mouse or the touch screen whichever is available.
- Change to the mmi CellEctor Plus software. Switch to Action and move the capillary down.
- Pump out 250nL of buffer – this aids to lift the cut region and make it buoyant – for larger cut regions more buffer may be needed.
- Move the stage manually to ensure the cut region is floating and then pump in 200nL.
- The cut region is now aspirated and collected in the capillary.
- Select Deposit and wait for the 3D robotic arm to move and deposit the cell directly onto the Ampligrids.
Ongoing development The method used here is still a mixture of manual and automated steps and so work is continuing. This study will look further at fine tuning the capillary landing position and pumping conditions to work towards a fully automated process. by Dr Anya L Hunt, MMI Regional Sales Manager (EMEA) & Forensic Specialist
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2010
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