Detection of smell print differences between nonmalignant and malignant prostate cells with an electronic nose.

AIM: To determine whether an electronic nose can differentiate cultured nonmalignant and malignant prostatic cells from each other and whether the smell print is secreted to the surrounding medium. MATERIALS & METHODS: Prostatic nonmalignant (EP-156T and controls) and malignant (LNCaP) cell lines, as well as conditioned and unconditioned media, were collected. The smell prints of the samples were analyzed by a ChemPro(®) 100 electronic nose device. The data were normalized and dimension reduction was conducted. The samples were classified and misclassification rates were calculated. RESULTS: The electronic nose differentiated the nonmalignant and malignant cell lines from each other, achieving misclassification rates of 2.9-3.6%. Cells did not differ from the conditioned medium but differed from the unconditioned medium (misclassification rates: 0.0-25.6%). CONCLUSION: Malignant and nonmalignant prostatic cell lines have distinct smell prints. Prostatic cancer cells seem to modify the smell print of their medium.

Functional characterisation of Fab'-fragments self-assembled onto hydrophilic gold surfaces.

Antibody Fab'-fragments have been immobilised on hydrophilic gold by direct self-assembly, and embedded in a matrix of non-ionic hydrophilic polymers, tris(hydroxymethyl)methylacrylamide, carrying lipoate terminal linking groups. Different polymers were synthesised, and co-adsorbed or post-adsorbed between the antibody fragments in order to optimise the antigen binding. Various factors were investigated that influence the activity of the immobilised Fab'-fragments for binding of the antigen, human IgG. The Fab'-fragments were immobilised in dense layers close to monolayer coverage, and the stoichiometric efficiency of immobilisation was up to 30%, with the human IgG also approaching monolayer coverage. The cleaning of the gold surface was a crucial factor in preservation of activity. Besides the usual treatment in hot ammonia/peroxide solution, hot DMSO appeared to be highly effective as a cleaning agent.