Development of an ELISA for the quantification of fibrin in canine tumours

Fibrin is found in most solid tumours, and there is speculation regarding i ts role in tumour invasion and metastasis. An assay to quantitate fibrin le vels in tissues would be a useful preliminary tool in assessing the above. Such an assay to quantitatively detect levels of fibrin in various types of canine tumour was developed. This procedure involved an ELISA using a mono clonal antibody (MAb 1H10) for canine fibrin as a capture antibody and a po lyclonal antibody to human fibrinogen conjugated to horseradish peroxidase as the detection antibody. The ELISA is calibrated against known concentrat ions of freeze-fractured fibrin derived from clotted dog plasma. The assay takes 3.5 hours, and concentrations as low as 0.1 mu g fibrin per millilite r of solubilised tumour can be readily detected. ELISA dilution curves for fibrin from various types of canine tumour were found to be parallel to the standard canine fibrin calibration curve. The intraassay and interassay va riabilities of the assay gave coefficients of variation in the range of 2.4 -4.5% and 7.2-7.8%, respectively, for the calibrator standard, in a concent ration range of 0.1-10 mu g/ml. Using this assay, we reported the levels of fibrin in three different types of malignant canine tissue. (C) 1999 Elsev ier Science Ltd. All rights reserved.