[The cut-off points used in chemiluminescent probes for the identification of mycobacteria]

441 strain of mycobacteria were exposed to probes marked with luminous material belonged to M. tuberculosis complex and M. avium complex. We analyzed the following points: 1. If the cut-off points obtained with our strains were in accordance to those recommended by the manufacturer, using two different luminometers. 2. If the correlation constant makes possible the conversion of the units form one luminometer to the units obtained with the other one. 3. Data for sensibility, specificity and predictive positive and negative values using different cut-off points. Cut-off points were different in all cases except for the data obtained with one luminometer using a probe belonged to M. tuberculosis complex. In this case the correlation constant could not be used. In contrast, whichever the luminometer employed was, we found no significant differences between sensibility, specificity and predictive values.