Provided are antibody conjugates, including a pair of cysteines crosslinked via a two-carbon bridge covalently connecting the sulfur atoms of the cysteines. Methods for making and using antibody conjugates are also provided. The compositions and methods of the present disclosure although particularly well suited to antibodies can be extended to other analytes having sulfur moieties such as proteins obtained from biological or artificial sources.

To develop a protecting group that facilitates separation and purification, after reaction, of a compound including a protected functional group, without solidifying or insolubilizing the compound. A xanthene compound of by General Formula (1) ##STR00001## (wherein Y is OR.sup.17 (R.sup.17 is a hydrogen atom or an active ester-protecting group), NHR.sup.18 (R.sup.18 is a hydrogen atom, or a linear or branched C.sub.1-C.sub.6 alkyl group or aralkyl group), an azide, a halogen atom, or a carbonyl group formed together with a methylene group; at least one of R.sup.1 to R.sup.8 is represented by Formula (2);
OR.sup.9X-A(2) and a residue is a hydrogen atom, a halogen atom, a C.sub.1-C.sub.4 alkyl group, or a C.sub.1-C.sub.4 alkoxy group, wherein R.sup.9 is a linear or branched C.sub.1-C.sub.16 alkylene group; X is O or CONR.sup.19 (R.sup.19 is a hydrogen atom or a C.sub.1-C.sub.4 alkyl group); and A is represented by Formula (3) or the like ##STR00002## (wherein R.sup.10, R.sup.11, and R.sup.12, the same or different, are a linear or branched C.sub.1-C.sub.6 alkyl group or an aryl group optionally including a substituent; R.sup.13 is a single bond or a linear or branched C.sub.1-C.sub.3 alkylene group; and R.sup.14, R.sup.15, and R.sup.16 are a linear or branched C.sub.1-C.sub.3 alkylene group)).

Compositions and methods for optically-verified, sequence-controlled polymer synthesis are described.

The present invention relates to -PNA monomers according to Formula I where substituent groups R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, B and P are defined as set forth in the specification. The invention also provides methodology for synthesizing compounds according to Formula I and methodology for synthesizing PNA oligomers that incorporate one or more Formula I monomers.

The present invention relates to -PNA monomers according to Formula I where substituent groups R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, B and P are defined as set forth in the specification. The invention also provides methodology for synthesizing compounds according to Formula I and methodology for synthesizing PNA oligomers that incorporate one or more Formula I monomers.

To develop a protecting group that facilitates separation and purification, after reaction, of a compound including a protected functional group, without solidifying or insolubilizing the compound.

A xanthene compound of by General Formula (1)

##STR00001## (wherein Y is OR.sup.17 (R.sup.17 is a hydrogen atom or an active ester-protecting group), NHR.sup.18 (R.sup.18 is a hydrogen atom, or a linear or branched C.sub.1-C.sub.6 alkyl group or aralkyl group), an azide, a halogen atom, or a carbonyl group formed together with a methylene group; at least one of R.sup.1 to R.sup.8 is represented by Formula (2);

OR.sup.9X-A(2) and a residue is a hydrogen atom, a halogen atom, a C.sub.1-C.sub.4 alkyl group, or a C.sub.1-C.sub.4 alkoxy group, wherein R.sup.9 is a linear or branched C.sub.1-C.sub.16 alkylene group; X is O or CONR.sup.19 (R.sup.19 is a hydrogen atom or a C.sub.1-C.sub.4 alkyl group); and A is represented by Formula (3) or the like

##STR00002## (wherein R.sup.10, R.sup.11, and R.sup.12, the same or different, are a linear or branched C.sub.1-C.sub.6 alkyl group or an aryl group optionally including a substituent; R.sup.13 is a single bond or a linear or branched C.sub.1-C.sub.3 alkylene group; and R.sup.14, R.sup.15, and R.sup.16 are a linear or branched C.sub.1-C.sub.3 alkylene group)).

A method for preparing peptides is disclosed, the method comprising a step of forming a peptide bond wherein the carboxyl group of a first amino acid or first peptide is activated and an amino group of the first activated amino acid or first peptide is protected by a protecting group having a water-solubility enhancing group and the activated carboxyl group of the first amino acid or first peptide is reacted with an amino group of a second amino acid or second peptide wherein said carboxyl group of the first amino acid or first peptide is activated in the absence of the second amino acid or second peptide. Peptides comprising a protecting group having a water-solubility enhancing group being bound to the amino group and an activated or free carboxyl group are also disclosed.

A method for preparing peptides is disclosed, the method comprising a step of forming a peptide bond wherein the carboxyl group of a first amino acid or first peptide is activated and an amino group of the first activated amino acid or first peptide is protected by a protecting group having a water-solubility enhancing group and the activated carboxyl group of the first amino acid or first peptide is reacted with an amino group of a second amino acid or second peptide wherein said carboxyl group of the first amino acid or first peptide is activated in the absence of the second amino acid or second peptide. Peptides comprising a protecting group having a water-solubility enhancing group being bound to the amino group and an activated or free carboxyl group are also disclosed.

The present invention relates to -PNA monomers according to Formula I where substituent groups R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, B and P are defined as set forth in the specification. The invention also provides methodology for synthesizing compounds according to Formula I and methodology for synthesizing PNA oligomers that incorporate one or more Formula I monomers.

The present invention relates to -PNA monomers according to Formula I where substituent groups R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, B and P are defined as set forth in the specification. The invention also provides methodology for synthesizing compounds according to Formula I and methodology for synthesizing PNA oligomers that incorporate one or more Formula I monomers.