Abstract: The present invention provides an aqueous solution composition containing elcatonin as an active ingredient used for hypercalcemia or bone Paget's disease or improvement of pain in osteoporosis, etc. and which is highly stable against shaking, light and heat. This composition contains an effective amount of elcatonin as an active ingredient and a monocarboxy compound and/or its water soluble salt thereof in a molar concentration of 0.05-20 mmol and has a pH of 5.0-6.5 and an ionic strength of .mu.=0.01-0.5. Preferred examples of the monocarboxy compound and its salts are acetic acid, lactic acid, L-histidine, sodium acetate, potassium acetate, sodium lactate, potassium lactate and L-histidine hydrochloride.

Abstract: A novel peptide of the formulaH--Ser--Arg--Arg--Ala--Gln--Asp--Phe--Val--Gln--Trp--Leu--Met--Asn--Thr--OHis the 16-29 fragment of glucagon and can be conjugated with a protein such as albumin or modified albumin using glutaraldehyde or 3-(2'-benzothiazolyl-dithio) propionate succinimide ester as a conjugation reagent. The conjugated peptide can be used to sensitize a mammal by administering the conjugated peptide subcutaneously, after which the blood is collected from the mammal and antibodies concentrated from the blood, which antibodies are then useful in assay methods for trace amounts of glucagon in human blood.

Abstract: A polyfunctional disulfide compound, useful as a cross-linking reagent having S--S exchange reactivity, of the formula ##STR1## wherein R is 2-benzothiazolyl or 2-pyridyl-N-oxide and X is a spacer group having an alkylene group directly bonded to each S--S group.

Abstract: A disulfide derivative, having S--S exchange reactivity, of the formulaR.sub.1 --S--S--R.sub.2 --CO--R.sub.3).sub.n R.sub.4 [I]wherein R.sub.1 is 2-benzothiazolyl or 2-pyridyl-N-oxide, R.sub.2 is alkylene having optionally free or protected functional groups, R.sub.3 is the carboxyl residue of an amino acid or lower polypeptide, R.sub.4 is carboxyl or a reactive derivative thereof or protected carboxyl or imidate, and n is 0 or 1.

Abstract: A disulfide compound of a carrier, having S--S exchange reactivity, of the formulaR--S--S--X.sub.1 --X.sub.2 --A [I]wherein R is 2-benzothiazolyl, X.sub.1 is a spacer group directly bound to the --S--S-- and comprises a plurality of carbon atoms in a straight or branched chain, X.sub.2 is an imide or amide bonding group, and A is an insoluble carrier selected from the group consisting of beads gel agarose residue, gamma-aminopropylated nylon beads residue and a residual group of partially reduced polyacrylonitrile porous granules or fibers.