Lymphokine production and purification.

A METHOD FOR PREPARING AND ISOLATING A TRANSFORMATION VECTOR CONTAINING CSF/CDNA IS DESCRIBED. THE METHOD COMPRISES: PREPARING RNA FROM A CELL THAT PRODUCES CSF; PREPARING POLYADENYLATED MESSENGER RNA FROM SAID RNA; PREPARING SINGLE STRANDED CDNA FROM SAID MESSENGER RNA; CONVERTING THE SINGLE STRANDED CDNA TO DOUBLE STRANDED CDNA; INSERTING THE DOUBLE STRANDED CDNA INTO TRANSFORMATION VECTORS AND TRANSFORMING BACTERIA WITH SAID VECTOR TO FORM COLONIES; PICKING POOLS OF 200 TO 500 COLONIES EACH AND ISOLATING PLASMID DNA FROM EACH POOL; TRANSFECTING THE PLASMID DNA INTO SUITABLE HOST CELLS FOR EXPRESSING CSF PROTEIN; CULTURING THE TRANSFECTED CELLS AND ASSAYING THE SUPERNATANT FOR CSF ACTIVITY; AND SELECTING CSF POSITION POOLS AND SCREENING THE COLONIES USED TO MAKE THE POOL TO IDENTIFY A COLONY HAVING CSF ACTIVITY. ALSO DESCRIBED ARE A CDNA CODING FOR A PROTEIN HAVING CSF ACTIVITY (I.E. CSF/CDNA), A MICROORGANISM OR CELL LINE TRANSFORMED WITH A RECOMBINANT VECTOR CONTAINING SUCH CSF/CDNA, AND A METHOD FOR PRODUCING CSF PROTEIN BY EXPRESSING SAID CSF/CDNA BY CULTURING A MICROORGANISM OR CELL LINE. THE INVENTION ALSO PROVIDES A METHOD OF PURIFYING THE CSF PROTEINS AND THE PURIFIED PROTEINS SO PRODUCED.