Equal number of cells per well (96 well plate) - (Nov/13/2007 )

What is the best way to assure that I get even number of cells per well of a 96 well plate? Multichannel pipettor or repeat pipettor. I've used repeat and this seems alright. For multichannel, I worry about putting cells/media into 'trough' and whether distribution is homogeneous. Also, I know this has been touched on before, but any other suggestions to account for this "edge effect" in 96 well plates?

My lab uses a multichannel, making sure to mix the media and cells in the trough thoroughly beforehand and between plates. I've not used a repeat, it may work just as well for you. Our lab does many plates at once, though, so we'd have to use the trough as a reservoir anyway. Companies do sell multichannel repeater/stepper micropipettors, if this is something you would be interested int.

As for accounting for edge effect, we put 100 uL of PBS in each well on the outside edge of the plate. That way, the only wells evaporating off to any major extent are just filled with PBS and don't matter. This is an imperfect solution, as ideally we'd like to use the full plate, but it is necessary to collect reliable data.