Abstract: Nitrogen mustard pro-drugs of the formula ##STR1## are disclosed where R is the residue of an .alpha.-amino acid RNH.sub.2 and M is a disubstituted amino "mustard" group, useful in antibody directed enzyme pro-drug therapy in the treatment of cancer.

Abstract: A method for treatment of tumors to which antibody A5B7 binds is disclosed. A5B7 is a monoclonal antibody which binds to carcinoembryonic antigen. The method comprises administering to a host in need of such treatment an effective amount of a system which comprises a conjugate comprising: antibody A5B7 or a humanized version of A5B7 linked to an enzyme selected from the group consisting of carboxypeptidase G2 (CPG2), nitroreductase, a human enzyme, a non-human enzyme rendered non-immunogenic in man and a humanized catalytic antibody; and a prodrug convertible under the influence of the conjugate into a cytotoxic drug.

Abstract: A treatment for tumors to which antibody A5B7 binds is disclosed. A5B7 is a monoclonal antibody which binds to carcinoembryonic antigen. The treatment comprises administering to a host in need of such treatment an effective amount of a system which comprises: a conjugate comprising antibody A5B7 or a humanized version of A5B7 linked to an enzyme selected from the group consisting of carboxypeptidase G2 (CPG2), nitroreductase, a human enzyme, a non-human enzyme rendered non-immunogenic in man and a humanized catalytic antibody; and a prodrug convertible under the influence of the conjugate into a cytotoxic drug.

Abstract: A reaction mixture handling device comprises a chamber for containing a reaction mixture having an open upper end for introduction of the mixture or components thereof, and an outlet at its lower end. Below the inlet a body of filter material is located together with reaction mixture retaining structure for retaining the reaction mixture in the chamber and which is rendered inoperative on application of a positive pressure to the chamber or a negative pressure to the underside of the filter material. The reaction mixture retaining structure may comprise an impermeable or hydrophobic member which is positioned between the outlet and the filter material and closes the outlet, part of the filter material which is made impermeable or hydrophobic and closes the outlet, or an openable member located beneath the filter material. Application of the differential pressure either causes the filter material to move away from the outlet to open the outlet, or opens the member to permit liquid to flow.

Abstract: A system for the automated analysis of large numbers of liquid samples, in which a multiplicity of sample tubes are loaded in racks into a cassette and the loaded cassette is transferred from station to station, with operations of sample insertion, dilution, reagent addition and withdrawal for filtering being performed at successive stations. At each station there is a separate processing module adapted to receive the cassette, each module including the apparatus necessary for performing one of the abovementioned operations on each individual sample tube when it is located at a particular operational location in the cassette. Each module also has members for shifting the racks in the cassette in such manner that all tubes pass through the operational location in turn while strictly maintaining the same order of sequence throughout the operations.