Patent ID: 7604956

Claim:
A super-sensitive sandwich immunoassay which can quantitate proteins with a detection level at less than 100 fg/ml by reducing biological background interference in the specimen to be tested comprising the steps of: (a) coating a testing substrate with an Abs (capture) solution and allowing incubation and bonding between the testing substrate and the Abs (capture) solution; (b) super stringent washing the testing substrate; (c) treating the testing substrate with a blocking reagent; (d) super stringent washing the testing substrate; (e) depositing a sample of physiologic fluid on the testing substrate; (f) super stringent washing the testing substrate; (g) applying an Abs (labeling) solution onto the testing substrate and allowing incubation; (h) super stringent washing the testing substrate; (i) applying a streptavidin based reagent onto the testing substrate; (j) super stringent washing the testing substrate; and (k) measuring and generating a signal representative of ultra-low amounts of labeled antibodies at detection levels less than 100 fg/ml, wherein the level of protein is ascertained using one or more of the following: a. multi photon detection (MPD) instrumentation which can quantitate proteins with a limit of detection of less than 10 fg/mg, using 125 I radiolabels; b. optical colorimeter readers having a signal capable of quantitating proteins at a limit of detection less than 50 fg/ml; wherein super-sensitivity is obtained by use of super-stringent washing wherein the protein detection ability is diminished by a factor greater than 3; and wherein the supersensitive washing is obtained using one or more of the following procedures: a. application of ultrasound; b. application of shock waves; c. movement of small magnetic actuator, wherein the rotational movement of the said magnetic actuator is induced by a strong external source of magnetic field; d. application of turbulent washing liquid having a temperature higher than room temperature e. application of turbulent washing liquid pH significantly different than pH=7 for at least 10 minutes; and f. washing using an application of a “slow-roll” technique.