An apparatus for measuring a signal from wells of sealed multi-well assay plates, the apparatus comprising: (a) a seal removal tool for removing seals from square or rounded-square shaped wells of said multi-well plates, wherein said seal removal tool comprises a piercing probe with a seal piercing tip, wherein said piercing probe comprises: (i) a piercing section with external surfaces that taper to a vertex so as to form said piercing tip at one end of a piercing direction, wherein said piercing section is pyramidal and has exposed cutting edges that extend in a radial direction from said piercing tip, wherein said exposed cutting edges cut a seal into sections and fold the sections against internal walls of said well; (ii) a seal displacement section, arranged adjacent to said piercing section along said piercing direction, with a cross-sectional shape, perpendicular to said piercing direction, that is a square or a rounded square; (iii) a plate stop section adjacent to said seal displacement section that defines the maximum distance of travel of said piercing probe into said wells, wherein the plate stop section is sized to prevent entry of the stop section into said well; and (iv) a pipetting probe; wherein said piercing probe has a through-hole parallel to said piercing direction and off-set from said piercing tip and said pipetting probe is movably located in said through-hole such that it can be withdrawn into said piercing probe during seal removal operations and extended from said piercing probe during pipetting operations; and (b) a detection system for measuring said signal from wells of said multi- well plate. (a) a seal removal tool for removing seals from square or rounded-square shaped wells of said multi-well plates, wherein said seal removal tool comprises a piercing probe with a seal piercing tip, wherein said piercing probe comprises: (i) a piercing section with external surfaces that taper to a vertex so as to form said piercing tip at one end of a piercing direction, wherein said piercing section is pyramidal and has exposed cutting edges that extend in a radial direction from said piercing tip, wherein said exposed cutting edges cut a seal into sections and fold the sections against internal walls of said well; (ii) a seal displacement section, arranged adjacent to said piercing section along said piercing direction, with a cross-sectional shape, perpendicular to said piercing direction, that is a square or a rounded square; (iii) a plate stop section adjacent to said seal displacement section that defines the maximum distance of travel of said piercing probe into said wells, wherein the plate stop section is sized to prevent entry of the stop section into said well; and (iv) a pipetting probe; wherein said piercing probe has a through-hole parallel to said piercing direction and off-set from said piercing tip and said pipetting probe is movably located in said through-hole such that it can be withdrawn into said piercing probe during seal removal operations and extended from said piercing probe during pipetting operations; and (i) a piercing section with external surfaces that taper to a vertex so as to form said piercing tip at one end of a piercing direction, wherein said piercing section is pyramidal and has exposed cutting edges that extend in a radial direction from said piercing tip, wherein said exposed cutting edges cut a seal into sections and fold the sections against internal walls of said well; (ii) a seal displacement section, arranged adjacent to said piercing section along said piercing direction, with a cross-sectional shape, perpendicular to said piercing direction, that is a square or a rounded square; (iii) a plate stop section adjacent to said seal displacement section that defines the maximum distance of travel of said piercing probe into said wells, wherein the plate stop section is sized to prevent entry of the stop section into said well; and (iv) a pipetting probe; (b) a detection system for measuring said signal from wells of said multi- well plate.