or label selected from the group consisting of where z is a linking group of from 1 to 20 carbons and 0 to 10 heterocarbons nh o s and may be branched or straight chain in general the compounds of this invention also have the following formula where r is a saturated or unsaturated linking group comprising one of the following where a is a linking group of from 1 to 20 carbons and from 0 to 10 heterocarbons nh o s either branched or straight chain in addition the general form of the immunogenic protein or polypeptide molecule or the protein or polypeptide molecule or label which is derivative via an amide disulfide thioether or ester bond to the molecule or label also to a compound of the formula is of the following where p is an antigenic protein or polypeptide or a protein polypeptide or label where x is at least one and not greater than 100 where r is a linking group comprising one of the following where a is a linking group of from 1 to 20 carbons and 0 to 10 heterocarbons nh o s either branched or straight chain where b is a linking group ultimately attached to a protein polypeptide or label selected from the group comprising where z is a linking group of from 1 to 20 carbons and 0 to 10 heterocarbons nh o s and may be branched or straight chain the preferred best mode compounds of this invention have the following formula where r is a linking group comprising one of.