A multi-channel analytical instrument (410; 510), comprising: - at least one illumination source (426; 531) arranged to be disposed on a first side of a specimen receiver having a plurality of wells spaced along a first dimension of the specimen receiver , the at least one illumination source (426; 531) operable to emit electromagnetic energy in an optical portion of the electromagnetic spectrum through the plurality of wells ; - at least one sensor (438; 738) arranged to be disposed on a second side of the specimen receiver opposite to the first side of the specimen receiver , the at least one sensor (438; 738) responsive to electromagnetic energy in an optical portion of the electromagnetic spectrum received from the plurality of wells to produce a signal indicative of at least one characteristic of the electromagnetic energy; - a plurality of first optical fibers coupled to the at least one illumination source (426; 531); characterized in that the multi-channel analytical instrument (410; 510) further comprises: - a plurality of first ball lenses (428; 528; 728) each arranged to be positioned proximate a respective one of a plurality of positions disposed on the first side of the specimen receiver and spaced from one another along the first dimension of the specimen receiver ; and - a plurality of second ball lenses (436; 536; 736) each arranged to be positioned proximate a respective one of a plurality of positions disposed on the second side of the specimen receiver and spaced from one another along the first dimension of the specimen receiver ; - wherein at least one of the plurality of first ball lenses (428; 528; 728) and at least one of the plurality of second ball lenses (436; 536; 736) are arranged in an optical path between respective pairs of one of the optical fibers of the first plurality of optical fibers and the at least one sensor (438; 738). - at least one illumination source (426; 531) arranged to be disposed on a first side of a specimen receiver having a plurality of wells spaced along a first dimension of the specimen receiver , the at least one illumination source (426; 531) operable to emit electromagnetic energy in an optical portion of the electromagnetic spectrum through the plurality of wells ; - at least one sensor (438; 738) arranged to be disposed on a second side of the specimen receiver opposite to the first side of the specimen receiver , the at least one sensor (438; 738) responsive to electromagnetic energy in an optical portion of the electromagnetic spectrum received from the plurality of wells to produce a signal indicative of at least one characteristic of the electromagnetic energy; - a plurality of first optical fibers coupled to the at least one illumination source (426; 531); - a plurality of first ball lenses (428; 528; 728) each arranged to be positioned proximate a respective one of a plurality of positions disposed on the first side of the specimen receiver and spaced from one another along the first dimension of the specimen receiver ; and - a plurality of second ball lenses (436; 536; 736) each arranged to be positioned proximate a respective one of a plurality of positions disposed on the second side of the specimen receiver and spaced from one another along the first dimension of the specimen receiver ; - wherein at least one of the plurality of first ball lenses (428; 528; 728) and at least one of the plurality of second ball lenses (436; 536; 736) are arranged in an optical path between respective pairs of one of the optical fibers of the first plurality of optical fibers and the at least one sensor (438; 738). <EOS>