Abstract: A seal device for a shaft is provided which has a maintenance seal which can reliably seal around the shaft without compression by rotation or pressing force, and which eliminates the necessity of readjustment after replacement of the seal packings. A seal packing is retained in a packing case housed in a casing, and a maintenance seal is housed under the packing case. A pressurizing means resiliently deforms a resilient body fitted so as to form a sealed space. The pressurizing means supplies pressurized fluid into the sealed space and inflates the resilient body to press it against the shaft. The pressurized fluid is discharged after repair of seal packings.

Abstract: A tripeptide ligand of the formula -X-Y-Argininal is used to purify plasminogen activators.

Abstract: A method for purifying tPA or a plasminogen activator having an active site resembling that of tPA from an impure solution thereof which comprises contacting the impure solution with a solid support having bound thereto a tripeptide of the formula: -X-Y-argininal, wherein X and Y are amino acids selected from the group consisting of pro, phe, trp and tyr. The method is also used with a tripeptide of the formula: -phe-Y-argininal, wherein Y is selected from the group consisting of phe, pro, trp, tyr, val, ile and glu(PEA).

Abstract: An improved immunoassay for the polypeptide hormone thymosin .alpha..sub.1 is described. The assay employs an improved antibody which is elicited by an immunogen which has been prepared by coupling [Tyr.sup.1 ]-thymosin .alpha..sub.1 to an immunogenic carrier protein using a bifunctional diazonium coupling agent.

Abstract: A novel affinity matrix material for trypsin and trypsin-like enzymes is disclosed. Methods employing this material to isolate and/or purify crude extracts containing trypsin and trypsin-like enzymes and to store the purified enzymes obtained are also disclosed.