A dark-field microscope apparatus comprising: an adapter housing configured to receive a portable electronic communication device and an objective lens , and to cause the objective lens to be registered with a camera lens of the portable electronic communication device when the portable electronic communication device is received by the adapter housing , wherein the adapter housing comprises a main body and a lens receiver that protrudes from the main body ; an electrically operated light source ; a dark-field condenser configured to condense light emissions generated by the electrically operated light source ; the objective lens received by the lens receiver ; a slide housing configured to receive at least a portion of an analytical slide and position the analytical slide between the dark-field condenser and the objective lens , wherein the slide housing is configured to receive at least portions of the lens receiver and the objective lens ; a first set screw configured to selectively promote engagement between the lens receiver and either (i) the slide housing or (ii) the objective lens , to adjust a first distance between the objective lens and the analytical slide ; and a second set screw configured to selectively promote engagement between the slide housing and the dark-field condenser , to adjust a second distance between the dark-field condenser and the analytical slide , wherein: the slide housing comprises a bore; the lens receiver comprises a first outer wall configured to fit into a first portion of the bore; and the dark-field condenser comprises a second outer wall configured to fit into a second portion of the bore. an adapter housing configured to receive a portable electronic communication device and an objective lens , and to cause the objective lens to be registered with a camera lens of the portable electronic communication device when the portable electronic communication device is received by the adapter housing , wherein the adapter housing comprises a main body and a lens receiver that protrudes from the main body ; an electrically operated light source ; a dark-field condenser configured to condense light emissions generated by the electrically operated light source ; the objective lens received by the lens receiver ; a slide housing configured to receive at least a portion of an analytical slide and position the analytical slide between the dark-field condenser and the objective lens , wherein the slide housing is configured to receive at least portions of the lens receiver and the objective lens ; a first set screw configured to selectively promote engagement between the lens receiver and either (i) the slide housing or (ii) the objective lens , to adjust a first distance between the objective lens and the analytical slide ; and a second set screw configured to selectively promote engagement between the slide housing and the dark-field condenser , to adjust a second distance between the dark-field condenser and the analytical slide , wherein: the slide housing comprises a bore; the lens receiver comprises a first outer wall configured to fit into a first portion of the bore; and the dark-field condenser comprises a second outer wall configured to fit into a second portion of the bore. the slide housing comprises a bore; the lens receiver comprises a first outer wall configured to fit into a first portion of the bore; and the dark-field condenser comprises a second outer wall configured to fit into a second portion of the bore. <EOS>