US 5,492,674 A · Evanescent wave immunoassay system

Abstract

Apparatus for assaying a fluid sample with radiation capable of exciting fluorescence in fluorescent material comprises a totally internally reflecting, unitary elongated substrate transmissive to both the excitation radiation and to the fluorescence. The fluorescent material includes at least a moiety of an antibody-antigen complex that includes a tag that will provide the fluorescence when excited by an evanescent wave generated by the excitation radiation. The substrate includes an elongated fiber and an integral lens formed to guide the optical radiation into the fiber within the bounds of a critical angle to assure total internal reflectance. A hollow elongated enclosure is disposed concentrically about and spaced from the fiber so as to provide an interspace of capillary dimensions. A test implement supports the elongated substrate, has a reservoir for receiving a fluid sample to be assayed, and is selectively movable to an operative position whereat the fluid sample is caused to flow onto the fiber and, by capillary action, into the interspace between the fiber and the enclosure. The apparatus further includes a source of the excitation radiation, refractive element for focusing the radiation toward the lens, detector for detecting fluorescence radiation emitted from an end of the fiber responsively to the excitation radiation, and optics frame for mounting all components in fixed relation to the lens for introducing the excitation radiation into the lens within the critical angle.

Claims25

Dependent claims

Single use disposable apparatus for assaying a fluid sample with excitation radiation from a radiation source, which radiation is capable of exciting fluorescence in fluorescent material, said apparatus comprising:

a totally internally reflecting, unitary elongated substrate transmissive to both the excitation radiation and to the fluorescence, said substrate including an elongated fiber and integral refractive means into which the radiation is to be introduced and at least a portion of the surface of which is adapted to contact the sample, said refractive means being formed to guide the optical radiation into said fiber within the bounds of a critical angle to assure total internal reflectance;
a coating of the fluorescent material on at least a portion of the surface of said fiber;
a hollow elongated enclosure disposed about and spaced from said fiber so as to provide an interspace of capillary dimension between said fiber and said enclosure, said elongated enclosure extending from a location adjacent said lens to an extreme end distant therefrom;
test implement means for supporting said elongated substrate and having reservoir means for receiving a fluid sample to be assayed and being movable between an inoperative position whereat the fluid sample is spaced from the elongated substrate and an operative position whereat the fluid sample is caused to flow onto said fiber and, by capillary action, into the interspace between said fiber and said enclosure.

1 more element

A single use disposable system for assaying a fluid sample with excitation radiation from a radiation source, which radiation is capable of exciting fluorescence in fluorescent material and recovering a coupled evanescent wave, said apparatus comprising:

a totally internally reflecting, unitary elongated substrate transmissive to both the excitation radiation and to the fluorescence, said substrate including an elongated fiber and integral refractive means into which the radiation is to be introduced and at least a portion of the surface of which is adapted to contact the sample, said refractive means being formed to guide the optical radiation into said fiber within the bounds of a critical angle to assure total internal reflectance;
a coating of the fluorescent material on at least a portion of the surface of said fiber;
a hollow elongated enclosure disposed about and spaced from said fiber so as to provide an interspace of capillary dimension between said fiber and said enclosure, said elongated enclosure extending from a location adjacent said lens to an extreme end distant therefrom;
test implement means for supporting said elongated substrate and having reservoir means for receiving a fluid sample to be assayed and being movable between an inoperative position whereat the fluid sample is spaced from the elongated substrate and an operative position whereat the fluid sample is caused to flow onto said fiber and, by capillary action, into the interspace between said fiber and said enclosure;
optics frame means including a platform for supporting said test implement means and being selectively movable to move said test implement means between the inoperative position and the operative position;
collimated light source means for directing an interrogating beam into said refractive means when said test implement means is in the operative position;
and
detector means for receiving reflected light radiation from said substrate through said refractive means coupled to an evanescent wave.

5 more elements

Dependencies are inferred from the claim text.

Evanescent wave immunoassay system

Life of this patent

Evanescent wave immunoassay system

Life of this patent

Abstract

Claims25