Method and apparatus for improved analytical fluorescent spectroscopy
First Claim
1. A method for fluorescent spectroscopy of a target substance comprising:
- isolating a target substance,tagging said target substance with a fluorescent tag having a long fluorescent decay lifetime compared to the longest of the decay lifetimes of competing untagged ambient substances,removing excess fluorescent tag,exciting the tagged target substance with at least one pulse of radiation, said pulse having a pulse duration which is short compared to the fluorescent decay lifetime of said fluorescent tag,detecting the fluorescence of said excited tagged target substances after the fluorescence of said ambient substances has substantially decayed.
1 Assignment
0 Petitions
Accused Products
Abstract
A method is disclosed whereby the molecules of a chemical substance to be measured, referred to as target molecules, are combined with fluorescent molecules having a relatively long fluorescent decay lifetime. These tagged target molecules are excited with an intense pulse of ultraviolet or visible radiation, and a detection system is gated on only after background fluorescence has substantially decayed, but while the fluorescent tag attached to the target molecules is still actively decaying. The amount of fluorescent tag emission which is measured is indicative of the target molecule content of the sample. An apparatus for improved fluorescent spectrofluorometry includes a pulsed excitation source and a gating means connected to a detection system for gating the detection system on after tagged target molecules have been excited and competing background fluorescence has substantially decayed, but before tagged target molecules have substantially decayed.
126 Citations
25 Claims
-
1. A method for fluorescent spectroscopy of a target substance comprising:
-
isolating a target substance, tagging said target substance with a fluorescent tag having a long fluorescent decay lifetime compared to the longest of the decay lifetimes of competing untagged ambient substances, removing excess fluorescent tag, exciting the tagged target substance with at least one pulse of radiation, said pulse having a pulse duration which is short compared to the fluorescent decay lifetime of said fluorescent tag, detecting the fluorescence of said excited tagged target substances after the fluorescence of said ambient substances has substantially decayed. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
-
- 13. In a method of fluorescent spectroscopy for a target substance wherein at least one pulse of excitation radiation of relatively short duration is directed toward the target substance the improvement comprising, combining with said target substance a fluorescent tag specific to the target substance with fluorescent decay lifetime long compared with the longest of the fluorescent decay lifetimes of competing untagged ambient substances and detecting said tagged target substance after fluorescence of competing ambient substances substantially decayed.
-
17. A method for fluorescent spectroscopy of a target substance amid ambient substances comprising;
-
tagging a target substance with a fluorescent tag specific to the target substance having a long fluorescent decay lifetime compared to the longest of the decay lifetimes of competing untagged ambient substances, removing excess fluorescent tag, exciting the tagged target substance for fluorescence with at least one pulse of radiation, said pulse having a pulse duration which is short compared to the fluorescent decay lifetime of said fluorescent tag, detecting the fluorescence of said excited tagged target substances after the fluorescence of said ambient substances has substantially decayed. - View Dependent Claims (18)
-
-
19. A fluorometer system for fluorescent spectroscopy of target substances comprising,
an amount of target substance amid untagged ambient substances, said target substance tagged with a fluorescent tag having a long fluorescent decay lifetime compared to the longest of the decay lifetimes of competing ambient substances, radiation means having an output directed at said target substance for exciting said tagged target substance into fluorescence with at least one pulse of radiation, said pulse having a pulse duration which is short compared to the long fluorescent decay lifetime of said fluorescent tag, a fluorescence detector, disposed for receiving fluorescence from said tagged target substance, having means for detecting said fluorescence after the fluorescence of competing ambient substances has substantially decayed and having gating means connected to said detecting means for gating on said fluorescence detector after said fluorescence of competing ambient substances has substantially decayed, and means for correlating the detected fluorescence of the tagged target substance with the amount of tagged target substance
Specification