Immunochemical detection of prion protein on dipsticks prepared with crystalline bacterial cell-surface layers.
BACKGROUND
Transmissible spongiform encephalopathy (TSE) represents a spectrum of diseases affecting humans and animals. A definitive diagnosis of TSEs is only possible by postmortem identification of pathologic prion protein in brain tissue that has been treated with protease. The pathologic protein is detected by Western blot analysis or ELISA methods. The bovine spongiform encephalopathy crisis and occurrence of a new variant of CJD has increased demand for rapid and simple assays.


METHODS
A dipstick assay has been developed for prion diagnosis based on a sandwich ELISA specific for prion protein, and crystalline bacterial cell-surface layers (S-layers) were used as an immobilization matrix. The usefulness of the dipstick assay was evaluated by determining the detection limit, comparison with other methods, and analysis of CJD samples.


RESULTS
The sensitivity of the prion dipsticks was similar to that published for time-resolved fluorescence ELISA methods. After protease treatment, pathologic prion protein could be detected specifically.


CONCLUSIONS
The dipstick assay is a sensitive and specific test useful for the detection of prion protein. The simplicity of the S-layer dipstick lends itself to a variety of potential applications including field diagnostics.
Völkel
Dirk
D
Baxter BioScience, Vienna, Austria.
Zimmermann
Klaus
K
Breitwieser
Andreas
A
Pable
Sabrina
S
Glatzel
Markus
M
Scheiflinger
Friedrich
F
Schwarz
Hans P
HP
Sara
Margit
M
Sleytr
Uwe B
UB
Dorner
Friedrich
F
D000942:Antigens, Bacterial / Q000276:immunology; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology; D015153:Blotting, Western; D001921:Brain / Q000473:pathology; D007562:Creutzfeldt-Jakob Syndrome / Q000473:pathology*; D003460:Crystallization; D019286:Endopeptidase K; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D000939:Epitopes; D006801:Humans; D011328:Prions / Q000032:analysis* / Q000276:immunology / Q000302:isolation & purification; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity
D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D000939:Epitopes; D011328:Prions; D011933:Reagent Kits, Diagnostic; D019286:Endopeptidase K