We thank Dr Mantelli and Dr Argueso for their letter regarding our article ‘Evaluation of ocular surface disorders: a new diagnostic tool based on impression cytology and confocal laser scanning microscopy.’

Our article describes the ability of antibodies against K12 and MUC1 (H-295) to distinguish clearly bewteen limbus/cornea and conjunctiva in impression cytology (IC) specimens using immunofluorescence and laser scanning confocal microscopy as read-outs. It was not our intention to debate the literature on MUC1, and nowhere in the article do we say that MUC1 is not expressed in cornea.

We are well aware and agree with the authors that ‘mucin antibodies can lead to considerable confusion if their specificity is poorly characterised.’ Our previous experience with impression cytology-based assays for clinical diagnoses1 2 and detection of immunofluorescent signals3 has taught us that antibodies should be thoroughly tested before being used. The polyclonal H-295 antibody we used in our work was, in fact, recommended for detection of Mucin1 (MUC1) of human origin by western blotting, immunoprecipitation and also immunofluorescence, and referenced in various peer-reviewed publications,4–7 where its specificity and efficacy were well described and documented.

We kindly disagree with the comment made by Dr Mantelli and Dr Argueso in their letter regarding our impression cytology specimens ‘not been properly permeabilised, which could explain lack of binding to the corneal impression cytology samples,’ …