Abstract: Image recording system for the evaluation of analytical test elements with a holding unit (8) into which the test elements are placed or onto which they are placed as well as a lens system (5) which records an image of the test elements on a CCD chip (3) and an evaluation unit that evaluates the image on the CCD chip or displays it on a monitor. The image recording system enables numerous test elements of different sizes to be evaluated at different wavelengths without requiring focussing by the user. The lens system used for this is a reducing optical system with an aperture on the side of the image of at least 0.7 and a distance between the CCD chip and the nearest lens of the lens system of less than 15 mm. In addition the distance between the nearest lens of the lens system and the CCD chip is kept constant to at least 10 &mgr;m in order to ensure an adequate sharpness. A compensator is described for keeping this distance constant.

Abstract: Compounds of the general formula Ia and Ib are described ##STR1## in which R.sup.1 and R.sup.2 are the same or different and represent hydrogen, straight-chain or branched C.sub.1 to C.sub.6 lower alkyl or an aryl group optionally substituted by electron-withdrawing groups, R.sup.3 denotes a cleavable group, W is hydrogen, halogen or a pseudohalogen and at least one of the groups R.sup.4 or R.sup.5 is a group stabilizing the dioxetane structure and at most one of the groups R.sup.4 or R.sup.5 represents hydrogen and X or Y represents oxygen, N-R or C(R).sub.2 in which R has the meanings stated for R.sup.1 and R.sup.2 or represents a mesomeric double bond or a carbonyl group and n denotes the number 0 or 1 and m denotes the number 1 or 2, as well as a process for their production. These compounds are new and can be used as substrates in immunological assays and in DNA diagnostics using activating agents for colour formation.

Abstract: For the detection of nucleic acids of definite sequence by hybridisation with a complementary nucleic acid probe which contains bound via a chemical bonding at least one hapten as labelling one uses, as hapten, a steroid which is bound vie a bridge of at least 4 atoms length to at least one position of the nucleic acid probe which does not participate in hydrogen bridge formation and detects the hybridised probe via an in turn labelled anti-hapten antibody.

Abstract: For the detection of nucleic acids of definite sequence by hybridisation with a complementary nucleic acid probe which contains bound via a chemical bonding at least one hapten as labelling one uses, as hapten, a steroid which is bound via a bridge of at least 4 atoms length to at least one position of the nucleic acid probe which does not participate in hydrogen bridge formation and detects the hybridised probe via an in turn labelled anti-hapten antibody.