System, device and method for reducing luminescence output shifts
Devices, systems, and methods for conducting chemiluminescent immunoassay testing and, more particularly, to initiating and monitoring a chemiluminescent reaction in a plurality of such assays, of different types, on a single immunoassay instrument, in a single procedure, using a plurality of labels and a triggering reagent combination are disclosed. Moreover, by including a base reagent injector assembly having an “e-channel” to provide a swirling turbulence to the base reagent immediately before it is introduced into the well of a cuvette containing a sample and an acid reagent. The added turbulence addresses the phenomenon referred to as “RLU shift,” in which the luminescence output can increase or decrease between assays.
1. A base reagent injector assembly for reducing Relative Light Unit (RLU) shift in chemiluminescent reactions, the injector assembly for dispensing a base reagent into a reaction receptacle for a chemiluminescent immunoassay test, the injector assembly comprising:
a lower injector portion having a proximal end, the proximal end configured to mechanically- and fluidly-couple to a RLU measurement unit, the lower injector portion further comprising a distal end, an injection channel, and a nozzle, the distal end having a chamber cavity; and
an upper injector portion having a cylindrical proximal end configured to releasably- and mechanically-couple to the lower injector portion when inserted into the chamber cavity, and the upper injector portion comprising a feed channel, the feed channel having an inlet and an outlet, therethrough,
wherein the outlet of the feed channel is configured to be in registration with the injection channel of the lower injector portion when the upper injector portion is releasably- and mechanically-coupled to the lower injector portion,
the feed channel is configured to create swirling turbulent flow in the base reagent before said base reagent is introduced into the injection channel, and
the creation of the swirling turbulent flow is insensitive to pump speed variations within a range of pump dispense speeds.
2. The injector assembly as recited in claim 1 , the injection channel of the lower injector portion has a first inner diameter in registration with the outlet of the feed channel and a second inner diameter at an opening in the nozzle, wherein the first inner diameter is larger than the second inner diameter.
3. The injector assembly as recited in claim 2 , wherein the first inner diameter is about 0.043 inches (about 1.1 mm) and the second inner diameter is about 0.033 inches (about 0.8 mm).
4. The injector assembly as recited in claim 1 , wherein the cylindrical proximal end of the upper injector portion includes a plurality of seal rings configured to provide a tight, interference fit with the chamber cavity of the lower injector portion when the upper injector portion is releasably- and mechanically-coupled to the lower injector portion.
5. The injector assembly as recited in claim 1 , wherein the feed channel has a spiral shape, the inlet located radially outward from a center of the spiral shape and the outlet located at the center of the spiral shape.
6. The injector assembly as recited in claim 1 , wherein the feed channel includes at least two 90 degree changes in direction.
7. The injector assembly as recited in claim 1 , wherein the injector assembly further comprises: injector tubing in registration with the inlet of the feed channel, and a vibrator configured to operationally-couple to the injector tubing and to provide turbulence-inducing vibrations to the injector tubing.
8. The injector assembly as recited in claim 7 , wherein the vibrator comprises:
a loudspeaker configured to couple to the injector tubing; and
a pulse generator configured to generate a pulse for selectively driving the loudspeaker.
9. The injector assembly as recited in claim 8 , wherein the pulse generator is adapted to generate pulses at a frequency between about 280 Hertz and 1000 Hertz.
10. The injector assembly as recited in claim 1 , wherein the injection channel of the lower injector portion and the inlet of the feed channel of the upper injector portion have respective axes that are not coaxial when the upper injector portion is releasably- and mechanically-coupled to the lower injector portion.
11. A chemiluminescent immunoassay testing system comprising:
a measurement unit configured to measure chemiluminescence of a sample after introduction of an acid reagent and a base reagent into a cuvette containing the sample; and
an injector assembly, adapted to reduce chemiluminescent Relative Light Unit (RLU) shift, comprising:
a lower injector portion having a proximal end, the proximal end configured to mechanically- and fluidly-couple to the measurement unit, the lower injector portion further comprising a distal end, an injection channel, and a nozzle, the distal end having a chamber cavity; and
an upper injector portion having a cylindrical proximal end configured to releasably- and mechanically-couple to the lower injector portion when inserted into the chamber cavity, and the upper injector portion comprising a feed channel, the feed channel having an inlet and an outlet, therethrough,
wherein the outlet of the feed channel is configured to be in registration with the injection channel of the lower injector portion when the upper injector portion is releasably- and mechanically-coupled to the lower injector portion,
the feed channel is configured to create swirling turbulent flow in the base reagent before said base reagent is introduced into the injection channel, and
the creation of the swirling turbulent flow is insensitive to pump speed variations within a range of pump dispense speeds.
12. The chemiluminescent immunoassay testing system as recited in claim 11 , wherein the measurement chamber includes a photomultiplier tube configured to measure chemiluminescence.
13. The chemiluminescent immunoassay testing system as recited in claim 11 , wherein the injector assembly further comprises: injector tubing in registration with the inlet of the feed channel, and a vibrator configured to operationally-couple to the injector assembly and adapted to provide turbulence-inducing vibrations to the injector assembly.
14. The chemiluminescent immunoassay testing system as recited in claim 13 , wherein the vibrator includes:
a loudspeaker configured to couple to the injector tubing; and
a pulse generator configured to generate a pulse for selectively driving the loudspeaker.
15. The chemiluminescent immunoassay testing system as recited in claim 14 , wherein the pulse generator is adapted to generate pulses at a frequency between 280 Hertz and 1000 Hertz.
16. The chemiluminescent immunoassay testing system as recited in claim 11 , wherein the injection channel of the lower injector portion and the inlet of the feed channel of the upper injector portion have respective axes that are not coaxial when the upper injector portion is releasably- and mechanically-coupled to the lower injector portion.
17. An upper injector portion of a injector assembly, the upper injector portion comprising:
a cylindrical proximal end configured to couple to a lower injector portion;
a spiral-shaped feed channel comprising an inlet and an outlet, the feed channel configured to create a swirling turbulent flow in a fluid passing from the inlet to the outlet, wherein the swirling turbulent flow is created when the fluid is passing from the inlet to the outlet within a range of pump dispense speeds and is insensitive to pump speed variations; and
a distal tubing interface configured to attach to an injector tubing,
wherein the outlet of the feed channel is configured to be in registration with an injection channel of the lower injector portion when the upper injector portion is coupled to the lower injector portion.
18. The upper injector portion as recited in claim 17 , wherein the feed channel includes at least two abrupt 90 degree changes in direction.
19. An injector assembly for dispensing a fluid into a reaction receptacle for a chemiluminescent immunoassay test, the injector assembly comprising:
a lower injector portion having a proximal end, the proximal end configured to couple to a measurement unit, the lower injector portion further comprising a chamber cavity; and
an upper injector portion having a cylindrical proximal end inserted into the chamber cavity and coupled to the lower injector portion, and the upper injector portion comprising a spiral-shaped feed channel, the feed channel having an inlet and an outlet,
wherein the outlet of the feed channel is in registration with the injection channel of the lower injector portion, and
the injector assembly is configured to change a structure of a micellar surfactant in the fluid before the fluid is introduced into the injection channel such that the change is insensitive to pump speed variations within a range of pump dispense speeds.
20. The upper injector portion as recited in claim 19 , wherein the injector assembly further comprises: injector tubing coupled to the inlet of the feed channel and configured to supply fluid to the inlet; and a vibrator coupled to the injector tubing and configured to provide vibrations to the fluid in the injector tubing.