Abstract: Novel isomers or mixtures of isomers of radioactive pyrethrinoids marked with iodine of the formula ##STR1## wherein X.sub.1 is selected from the group consisting of halogen and --CF.sub.3, X.sub.2 is a halogen, R is the residue of an amino acid of the formula R--NH.sub.2 or a derivative thereof containing an iodine acceptor group and marked with iodine.sup.125 or iodine.sup.131, process for their preparation and intermediates and their use in radioimmunological determination.

Abstract: Novel radioactive estradienes labelled with tritium of the formula ##STR1## wherein .sup.3 H is tritium and R is selected from the group consisting of hydrogen, alkyl of 1 to 6 carbon atoms and acyl of an organic carboxylic acid of 1 to 10 carbon atoms and the study and radioimmunological determination of non-radioactive 11.beta.-(4-dimethylaminophenyl)-17.alpha.-(prop-1-ynyl)-.DELTA..sup.4,9 -estradiene-17.beta.-ol-3-one and its metabolites in biological fluids and novel intermediates.

Abstract: Novel radioactive estradienes labelled with iodine of the formula ##STR1## in the form of their syn or anti isomers or mixtures thereof wherein the wavy line indicates anti or syn position, R is selected from the group consisting of hydrogen, alkyl of 1 to 6 carbon atoms and acyl of an organic carboxylic acid of 1 to 12 carbon atoms and R.sub.1 is the residue of an amino acid R.sub.1 NH.sub.2 possessing an iodine acceptor group or a derivative thereof labelled with iodine .sup.125 or .sup.131 and their preparation and novel intermediates, antigens prepared from the compounds of formula I and bovine seric albumin or human seric albumin and their preparation and their use for the preparation of antibodies.

Abstract: Novel radioactive .DELTA..sup.4,9,11 -estratrienes marked with iodine 125 or 131 having the formula ##STR1## wherein R is selected from the group consisting of hydrogen, alkyl of 1 to 6 carbon atoms and acyl of an organic carboxylic acid of 2 to 12 carbon atoms, R.sub.1 is the reminder of an amino acid of the formula R.sub.1 NH.sub.2 or a derivative thereof being marked with iodine 125 or 131 and the wavy lines indicate the --OR is in the .alpha.- or .beta.-position and the oximido group is in the syn or anti position, a process and intermediates for their preparation, antigens prepared therefrom and use thereof to prepare antibodies.