Inter alia , a luminometer for an automated analyzer to assay an analyte in a test sample in a cuvette in which the product of the test reaction includes a chemiluminescent labeled reagent and the product being suspended in an acid solution, the said cuvette having a bottom wall, side wall and an open top, characterised in that it comprises:

(a) a cuvette transport for conveying the said cuvette in a horizontal plane from an entrance point to a base solution dispense point and to an exit point;
(b) dispense means at the said base solution dispense point for dispensing a base solution into the said cuvette to cause a chemiluminescent flash;
(c) an instrument at the said base solution dispense point for measuring the intensity of the said flash;
and
(d) control means including a central processing unit for coordinating the said cuvette transport, the said dispense means and the said instrument is disclosed.