A novel hybridoma antibody (PASE/4LJ) to human prostatic acid phosphatase suitable for immunohistochemistry.

A murine monoclonal antibody PASE/4LJ to prostatic acid phosphatase (PAP) was used to immunostain a wide variety of sections of benign and malignant tissues (654 blocks). Non-neoplastic adult and fetal prostatic glands, primary and metastatic prostatic carcinomas, and scattered cells in prostatic and penile urethra were positive. Rat, dog and rabbit prostates were negative. Nine of 400 tumours of non-prostatic origin showed some positivity: 6/36 carcinoids, 1/9 islet cell tumours, 1/55 ovarian adenocarcinomas (serous) and one carcinosarcoma of the lung (epithelial portion). Positive staining was seen in islet cells in 4/5 specimens of normal pancreas, and in 4/9 blocks of normal pancreas surrounding a pancreatic tumour. Loops of Henle, maculae densae, and distal tubules in 10/10 fetal and 2/9 adult kidneys were also positive, with proximal tubules and collecting ducts negative. All other 159 blocks of non-neoplastic adult and fetal tissues were negative. The antibody was also affinity purified from ascitic fluid, and shown not to inhibit the enzyme activity of prostatic acid phosphatase.

Optimization and batch production of DTPA-labelled antibody kits for routine use in 111In immunoscintigraphy.

A procedure for conjugating antibodies in batches with DTPA is described which yields pharmaceutical grade preparations that can be kept in frozen storage until required. Routine radiolabelling is then simply performed by adding 111In chloride to the sterile 'kit' vial. After 1h, a DTPA solution is added to make the preparation ready for use in patients. The effects of pH, DTPA to antibody ratio, and time of reaction were investigated to optimize the preparation. By this method the antibody-DTPA conjugates may be prepared and the quality control performed at regional nuclear medicine centres where facilities and expertise already exist. These 'kits' can then be distributed to other departments where the 111In is added as and when required in a similar way to the preparation of other radiopharmaceuticals.

An improved iodogen method of labelling antibodies with 123I.

A reliable method for radioiodinating antibodies is described. The reaction is initiated by the addition of a fine suspension in buffer of iodogen particles formed in a novel way. The addition of an acetone solution of Iodogen to phosphate-buffered saline yields a uniform suspension of 3.0 micron diameter particles. This preparation has been used to label polyclonal anti-prostatic acid phosphatase (PAP) antibodies with up to 185 MBq of iodine-123 mg-1. Labelling efficiencies of 92% are achieved in a reaction time of less than 5 min. Such labelled antibodies are expected to be of use in the immunoscintigraphy of patients with prostatic cancer. The reaction parameters have been optimized and the method is particularly suitable for routine use.

Chemiluminescence immunoassay of plasma progesterone, with progesterone-acridinium ester used as the labeled antigen.

This simple solid-phase chemiluminescence immunoassay for measurement of progesterone in extracts of venous plasma has sensitivity and precision similar to that of conventional radioimmunoassay with use of a tritiated antigen. The labeled antigen, 11 alpha-progesteryl-2-succinoyltyramine-4-(10-methyl)-acridini um-9-carboxylate, and a monoclonal antibody to progesterone-11 alpha-succinyl-bovine serum albumin are incubated with a 100-microL aliquot of plasma extract (equivalent to 20 microL of plasma) and 50 microL of a suspension of an IgG fraction of a donkey antiserum to mouse immunoglobulins, covalently attached to cellulose particles. After the antibody-binding reaction (60 min at 4 degrees C), 1 mL of phosphate buffer is added to each tube, the tubes are centrifuged (5 min, 1500 X g), and the supernatant fluid is aspirated. The washing step is repeated and diluted hydrochloric acid (50 mmol/L, 50 microL) is added to the pellet. Luminescence is initiated by oxidation with dilute sodium hydroxide/hydrogen peroxide. The signal is integrated over 10 s. The light yield is inversely proportional to the progesterone concentration in the standard or sample.