System and method for monitoring a reaction within a receptacle vessel

1. A system for monitoring reactions within a plurality of receptacle vessels comprising:

an incubator having a temperature-controlled chamber;

a movable receptacle carrier disposed within the temperature-controlled chamber and configured to carry a plurality of receptacle vessels and to move the receptacle vessels within the temperature-controlled chamber;

one or more fixed fluorometers configured to measure a fluorescent emission and positioned with respect to the receptacle carrier to measure fluorescent emissions from receptacle vessels carried on the receptacle carrier into an operative position with respect to each fluorometer;

one or more fluorescent reference standards mounted on the receptacle carrier; and

a controller configured to control operation of the receptacle carrier and the one or more fluorometers and to:

move the receptacle carrier with respect to the one or more fluorometers to place a receptacle vessel into an operative position with respect to each fluorometer;

activate each fluorometer to measure the fluorescent emission intensity from a sample contained in the receptacle vessel that is in the operative position with respect to the fluorometer;

determine a characteristic of the reaction based on the measured fluorescent emission intensity from the sample contained in the receptacle vessel;

move the receptacle carrier with respect to the one or more fluorometers to place a fluorescent standard into optical communication with at least one fluorometer;

activate the fluorometer to measure the fluorescent emission intensity of the fluorescent standard that is in optical communication with the fluorometer;

determine a deviation of the measured fluorescent emission intensity of the fluorescent standard from an expected fluorescent emission intensity;

if the deviation exceeds a threshold, generate an error signal; and

if the deviation does not exceed a threshold, continue operation of the system.

2. In an instrument configured to determine a characteristic of a sample from the intensity of a fluorescent emission from the sample, wherein the sample is contained in a receptacle vessel that is carried on a movable receptacle carrier, and the intensity of the fluorescent emission is measured by a fluorometer that is fixed with respect to the receptacle carrier and is constructed and arranged to measure the intensity of fluorescent emission from a sample contained in a receptacle vessel that is moved by the receptacle carrier into a detection zone with respect to the fluorometer, an automated method for detecting failure or deteriorated performance of the fluorometer with a fluorescent reference standard mounted on the receptacle carrier, the method comprising the steps of:

(a) moving the receptacle carrier with respect to the fluorometer to periodically place the receptacle vessel into the detection zone of the fluorometer, and taking one or more measurements of the intensity of the fluorescent emission from the sample contained in the receptacle vessel with the fluorometer;

(b) before or after performing step (a), moving the receptacle carrier with respect to the fluorometer to place the fluorescent reference standard into optical communication with the fluorometer, and taking a test measurement of the emission intensity of the fluorescent reference standard;

(c) determining a deviation of the test measurement taken in step (b) from a predetermined baseline emission intensity of the fluorescent reference standard;

(d) if the deviation determined in step (c) exceeds a threshold, generate an error signal; and

(e) if the deviation determined in step (c) does not exceed the threshold, continue operation of the instrument by repeating steps (a) through (c) until a stop condition is reached.

3. The method of claim 2 , further comprising the step of determining the baseline emission intensity by:

prior to step (a), moving the receptacle carrier with respect to the fluorometer to place the fluorescent reference standard into optical communication with the fluorometer;

taking an initial measurement of the emission intensity of the fluorescent reference standard with the fluorometer; and

storing the initial measurement as the predetermined baseline emission intensity.

4. The system of claim 1 , wherein the fluorescent reference standard is a fluorescent plastic.

5. The system of claim 4 , wherein the fluorescent reference standard is in the shape of a disk.

6. The system of claim 1 , wherein the fluorescent reference standard is situated beneath a reaction vessel.

7. The system of claim 1 , wherein the fluorescent reference standard is out of focus relative to the fluorometer.

8. The system of claim 1 , wherein the fluorescent reference standard is in focus relative to the fluorometer.

9. The method of claim 2 , wherein the fluorescent reference standard is a fluorescent plastic.

10. The method of claim 9 , wherein the fluorescent reference standard is in the shape of a disk.

11. The method of claim 2 , wherein the fluorescent reference standard is situated beneath a reaction vessel.

12. The method of claim 2 , wherein the fluorescent reference standard is out of focus relative to the fluorometer.

13. The method of claim 2 , wherein the fluorescent reference standard is in focus relative to the fluorometer.

14. The method of claim 3 , wherein the fluorescent reference standard is a fluorescent plastic.

15. The method of claim 14 , wherein the fluorescent reference standard is in the shape of a disk.

16. The method of claim 3 , wherein the fluorescent reference standard is situated beneath a reaction vessel.

17. The method of claim 3 , wherein the fluorescent reference standard is out of focus relative to the fluorometer.

18. The method of claim 3 , wherein the fluorescent reference standard is in focus relative to the fluorometer.