Abstract: A method for detecting nonsense mutations and frameshift mutations in a test nucleic acid fragment which is simple and may be used even when the size of the test nucleic acid fragment is large is disclosed. The method involves inserting the test nucleic acid fragment into a vector containing a promoter, a translational initiation codon, and a reporter gene, and transforming a host cell with the vector to express a fusion polypeptide. The production of the fusion polypeptide is assayed for in the host cell, and non-production of the fusion polypeptide is indicative of a nonsense and/or frameshift mutation in the test nucleic acid fragment.

Abstract: Substantially pure neocarzinostatin anticancer agents have the formula (A):(SMA)--(NCS)--(SMA) (A)wherein (NCS) is a divalent neocarzinostatin residue and (SMA) comprises the monovalent residue of a partially half-esterified styrene-maleic acid copolymer having a weight-average molecular weight of from 800 to 2,500, said (NCS) residue being bonded to said (SMA) residues via amide linkages formed between primary amino groups of the neocarzinostatin molecule and carbonyl groups of the partially half-esterified styrene-maleic acid copolymer.

Abstract: Substantially pure neocarzinostatin anticancer agents have the formula (A):(SMA)-(NCS)-(SMA) (A)wherein (NCS) is a divalent neocarzinostatin residue and (SMA) comprises the monovalent residue of a styrene-maleic acid copolymer having a weight-average molecular weight of from 800 to 2,500, said (NCS) residue being bonded to said (SMA) residues via amide linkages formed between primary amino groups of the neocarzinostatin molecule and carbonyl groups of the styrene-maleic acid copolymer.

Abstract: Novel neocarzinostatin anticancer agents have the formula:(SMA)--(NCS)wherein (NCS) is a neocarzinostatin residue, n is an integer ranging from 1 to 35, and (SMA) comprises the residue of a half-esterified styrene-maleic acid copolymer having an average molecular weight of from 1,000 to 10,000, said half-esterified styrene-maleic acid copolymer comprising (i) styrene residues, (ii) maleic acid residues covalently bonded to (NCS), (iii) free maleic acid residues, and (iv) half-esterified maleic acid residues, and further wherein the total amount of said residues (ii) and (iii) ranges from an average of 0.1 per molecule to 60 mole % of said (SMA).

Abstract: Neocarzinostatin derivatives having the formula; ##STR1## wherein N represents a neocarzinostatin residue, and R.sub.1 +R.sub.2 represents a residue of polystyrene-maleic acid copolymer having a molecular weight of 2,500 to 80,000. These neocarzinostatin derivatives are prepared by reacting neocarzinostatin with a polystyrene-maleic acid copolymer containing at least one maleic anhydride residue per molecule.The neocarzinostatin derivatives exhibit anticarcinogenic activity.