Interrupted, vertical flow testing device
In a vertical flow immunoassay testing device, the fluid specimen is deposited in a sampling well whose inclined walls and filtration material separate mucus and other adhesive matters from the more fluid components. The mixing of the specimen with a buffer solution is triggered by the closure of the device's cap. The flow of the buffered specimen from a first chamber where it is exposed to a collodial gold conjugate to a second chamber holding a chromatographic test strip is temporarily interrupted by a holding reservoir. The specimen does not freely flow into the strip until the reservoir begins to overflow. The delay provides an incubation time for a better affinity binding of the specimen and regulates its flow through the strip.
1 . In an immunoassay flow testing device wherein a fluid specimen in a buffered solution is first contacted with a colloidal conjugate in a first part of said device, then applied to a chromatographic testing strip in a second part of said device, an improvement which comprises a flow interrupting reservoir between said first and said second parts.
2 . The improvement of claim 1 which further comprises means for restricting flow from said reservoir to said strip.
3 . The improvement of claim 2 , wherein said means for restricting comprises an escape port in an upper part of said reservoir.
4 . A flow immunoassay testing device which comprises:
a first chamber holding a colloidal gold conjugate;
a second chamber holding at least one chromatographic testing strip; and
a flow-interrupting reservoir of a given capacity between said first and second chambers.
5 . The device of claim 4 which further comprises:
a supply of buffer liquid; and
means for triggering the dispensing of said supply into said first chamber.
6 . The device of claim 5 which further comprises a sampling well in communication with said first chamber.
7 . The device of claim 6 , wherein said sampling well comprises a funnel-shaped internal wall.
8 . The device of claim 5 , wherein said means for dispensing comprises:
a vessel holding said supply of buffer, said vessel having an opening in an upper region and a dispensing port in a lower region;
a membrane sealing said opening; and
means for puncturing said membrane to allow dispensing of said supply through said port under atmospheric pressure.
9 . The device of claim 8 , wherein said device further comprises a cap covering said sampling well and vessel; and
at least one prong extending from said cap toward said membrane, said prong being shaped and dimensioned to puncture said membrane when said cap is placed over said sampling well and vessel.
10 . The device of claim 5 which further comprises an absorbing pad in contact with a portion of said strip.
11 . The device of claim 4 , wherein said reservoir has an escape port in an upper part thereof;
whereby a liquid wash from said first chamber must accumulate into said reservoir up to the level of said escape port before flowing freely into said second chamber.
12 . The device of claim 6 which further comprises filtration material in said sampling well.
13 . The device of claim 5 , wherein said supply of buffer liquid is adjusted to create a minor overflow of said reservoir.
14 . The device of claim 4 , wherein said second chamber holds a plurality of strips each having a plurality of chromatographic test lines.