Abstract: Novel pyridine compounds having the formula R.sup.1 -S-S-A-Z are disclosed, in which formula R.sup.1 is 2-pyridyl, 5-nitro-2-pyridyl or 4-pyridyl, A is a hydrocarbon residue having 1-10 carbon atoms and Z is a group ##STR1## or acid addition salts of the last mentioned group, where n is 2 or 3, R.sup.1 has the same significance as R.sup.1 above and is equal thereto and R.sup.2 is methyl or ethyl. These compounds are particularly useful as bifunctional coupling agents and as thiolating agents.

Abstract: A reagent for use in immunochemical assay methods carried out in the presence of an aqueous liquid, which reagent comprises a conjugate of one or more molecules of immunoglobulin and one or more units of an analytically indicatable group which molecules and units are bound together via bridges containing the group, --S--S--, said conjugate being soluble in said aqueous liquid.

Abstract: A method of carrying out assaying methods involving biospecific affinity reactions in which there is used a component (I), which is labelled with at least one analytically indicatable group and is soluble in the liquid in whose presence the biospecific affinity reaction is carried out, for reaction with a counterpart (II) which exhibits biospecific affinity to (I) and optionally also one or more additional counterparts exhibiting biospecific affinity to (I) and/or (II), and forming an insoluble conjugate in which the labelled component (I) is incorporated and which conjugate is separated from the liquid phase, whereafter the analytically indicatable group is assayed in the insoluble conjugate, said method being characterized in that the analytically indicatable group is bound to the component (I) with a splittable bond of covalent nature and/or one of said counterparts is bound to a carrier, which is insoluble in said liquid, with a splittable bond of covalent nature, said splittable bonds being splittable un

Abstract: A novel class of reactive derivatives of polymers containing HS-groups is disclosed in which derivatives a number of the HS-groups are converted to a disulphide group of the formula -S-S-A-Z, where A is a hydrocarbon residue having 1-10 carbon atoms and Z is a group ##STR1## or acid addition salts of the last mentioned group, where n is 2 or 3, R.sup.1 is 2-pyridyl, 5-nitro-2-pyridyl or 4-pyridyl and R.sup.2 is methyl or ethyl. The novel derivatives may be used, for example, as thiolating agents or as carriers for e.g. enzymes or other proteins etc.

Abstract: Novel pyridine compounds having the formula R.sup.1 -S-S-A-Z are disclosed, in which formula R.sup.1 is 2-pyridyl, 5-nitro-2-pyridyl or 4-pyridyl, A is a hydrocarbon residue having 1-10 carbon atoms and Z is a group ##STR1## or acid addition salts of the last mentioned group, where n is 2 or 3, R.sup.1 has the same significance as R.sup.1 above and is equal thereto and R.sup.2 is methyl or ethyl. These compounds are particularly useful as bifunctional coupling agents and as thiolating agents.