Objective quantitation of serum antibody titres against Enterobacteriaceae using indirect immunofluorescence, read by videocamera and image processing system.

A new way of measuring indirect immunofluorescence (IIF) of microscopic bacterial slide preparations by videocamera and an image processing system is presented. This method is compared with the conventional method of reading the slides by eye. The advantages of this new approach are objective reading, greater accuracy and easier performance. We have applied the method to measure serum antibody titres against endogenous Enterobacteriaceae. The method offers the opportunity to combine IIF with automatic morphological analysis, thereby maximally exploiting the possibilities of the immunofluorescence technique.