The pipettes, 40 and 42, are positioned and operated by {TAIL ~ a pipette mechanism} 44 mechanically connected to the pipettes 40 and 42, as indicated by {HEAD ~ dashed lines} 
The pipettes , 40 and 42 , are positioned and operated by { TAIL ~ a pipette mechanism } 44 mechanically connected to the pipettes 40 and 42 , as indicated by { HEAD ~ dashed lines }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD