Abstract: A method for recovering precious metals from carbonaceous ore comprising leaching the ore with a lixiviant solution and then preg-robbingly concentrating the precious metal-lixiviant complexes in solution on to the native carbonaceous component of the ore for subsequent recovery. The preg-robbing capacity of the native carbonaceous component of the ore can be augmented by adding recycled carbonaceous matter or finely ground carbon to the ore-lixiviant mixture.

Abstract: A variety of processes for recovering gold from gold ore are disclosed. Briefly, the methods include culturing at least one microorganism species capable of producing cyanide ion under conditions wherein the microorganism produces cyanide ion, thus forming a cyanide ion-containing culture; contacting the cyanide ion-containing culture with gold ore, causing production of gold ion-cyanide ion complexes and biosorption of said complexes to said cultures; and recovering gold from the culture. The invention may be practiced with a variety of microorganisms, including Chromobacterium violaceum and Chlorella vuloaris.

Abstract: A method for producing tissue plasminogen activator (t-PA) in eukaryotic host cells is disclosed. Enhanced levels of t-PA production are obtained by co-amplification of the t-PA gene through treatment of cultures transformed with mutant or wild-type DHFR with methotrexate.

Abstract: Sequential degradation of peptides for sequencing purposes by successive cleavage of amino acids from one end of the peptide chain is performed in an adsorption column with flows of the degradation reagents and wash liquids passing through the column in both directions. Migration of the peptide in one direction is thereby compensated by a subsequent migration in the other, and loss of peptide from the column over repeated cleavages is avoided. In preferred embodiments, the column contains two serially arranged adsorbent zones with differing adsorption characteristics, and the directions of flow of the various system components through the column are selected with a view toward a difference in peptide partitioning between the stationary and mobile phases in one zone vs. the other. The result is that any migration of the peptide occurring at any stage of a given cycle of the procedure occurs at a greater rate toward the zone interface than away from it.

Abstract: Human tissue plasminogen activator (t-PA) is produced in useful quantities using recombinant DNA techniques. The invention disclosed thus enables the production of t-PA free of contaminants with which it is ordinarily associated in its native cellular environment. Methods, expression vehicles and various host cells useful in its production are also disclosed. A truncated human tissue plasminogen activator consisting essentially of amino acids 69-527 is produced using recombinant DNA techniques.

Abstract: A variety of processes for recovering gold from gold ore are disclosed. Briefly, the methods include culturing at least one microorganism species capable of producing cyanide ion under conditions wherein the microorganism produces cyanide ion, thus forming a cyanide ion-containing culture; contacting the cyanide ion-containing culture with gold ore, causing production of gold ion-cyanide ion complexes and biosorption of said complexes to said cultures; and recovering gold from the culture. The invention may be practiced with a variety of microorganisms, including Chromobacterium violaceum and Chlorella vulgaris.

Abstract: A variety of processes for recovering gold from gold ore are disclosed. Briefly, the methods include culturing at least one microorganism species capable of producing cyanide ion under conditions wherein the microorganism produces cyanide ion, thus forming a cyanide ion-containing culture; contacting the cyanide ion-containing culture with gold ore, causing production of gold ion-cyanide ion complexes and biosorption of said complexes to said cultures; and recovering gold from the culture. The invention may be practiced with a variety of microorganisms, including Chromobacterium violcaceum and Chlorella vulgaris.

Abstract: A device for the determination of amino acid sequence of a polypeptide comprises two new features offering great advantages in the cost and efficiency of operation of amino acid sequencers. The sequencer is provided with the capability for the bidirectional flow of sequencing reagents and contains a sample chamber having a bicompositional adsorbent for the polypeptide.

Abstract: A method for producing tissue plasminogen activator (t-PA) in eukaryotic host cells is disclosed. Enhanced levels of t-PA production are obtained by co-amplification of the t-PA gene through treatment of cultures transformed with mutant or wild type DHFR with methotrexate.

Abstract: Human tissue plasminogen activator (t-PA) is produced in useful quantities using recombinant DNA techniques. The invention disclosed thus enables the production of t-PA free of contaminants with which it is ordinarily associated in its native cellular environment. Methods, expression vehicles and various host cells useful in its production are also disclosed.

Abstract: Human tissue phasminogen activator (t-PA) is produced in useful quantities using recombinant DNA techniques. The invention disclosed thus enables the production of t-PA free of contaminants with which it is ordinarily associated in its native cellular environment. Methods, expression vehicles and various host cells useful in its production are also disclosed.