Liposome polymerase chain reaction assay for the sub-attomolar detection of cholera toxin and botulinum neurotoxin type A.
We describe an ultrasensitive immunoassay for detecting biotoxins that uses a liposome with encapsulated DNA reporters, and ganglioside receptors embedded in the bilayer, as the detection reagent. After immobilization of the target biotoxin by a capture antibody and co-binding of the detection reagent, the liposomes are ruptured to release the reporters, which are quantified by real-time polymerase chain reaction. The new assays for cholera and botulinum toxins are several orders of magnitude more sensitive than current detection methods. A single 96-well microtiter plate can analyze approximately 20 specimens, including calibration standards and controls, with all measurements conducted in triplicate. Using pre-coated and blocked microtiter plates, and pre-prepared liposome reagents, a liposome polymerase chain reaction assay can be carried out in about 6 h.
Mason
Jeffrey T
JT
Department of Biophysics, Armed Forces Institute of Pathology, 1413 Research Boulevard, Rockville, Maryland 20850, USA. mason@afip.osd.mil
Xu
Lixin
L
Sheng
Zong-mei
ZM
He
Junkun
J
O'Leary
Timothy J
TJ
D019274:Botulinum Toxins, Type A / Q000032:analysis*; D002772:Cholera Toxin / Q000032:analysis*; D006801:Humans; D008081:Liposomes; D008297:Male; D016133:Polymerase Chain Reaction / Q000379:methods*
D008081:Liposomes; D002772:Cholera Toxin; D019274:Botulinum Toxins, Type A