Apparatus and method for high-throughput preparation and spectroscopic classification and characterization of compositions
Systems and methods are described that allow the high-throughput preparation, processing, and study of arrays of samples, each of which comprises at least one compound. Particular embodiments of the invention allow a large number of experiments to be performed in parallel on samples that comprised of one or more compounds on the milligram or microgram quantities of compounds. Other embodiments of the invention encompass methods and devices for the rapid screening of the results of such experiments, as well as methods and devices for rapidly determining whether or not similarities exist among groups of samples in an array. Particular embodiments of the invention encompass methods and devices for the high-throughput preparation of different forms of compounds (e.g., different crystalline forms), for the discovery of new forms of old compounds, and for the discovery of new methods of producing such forms. Embodiments of the invention also allow for the high-throughput determination of how specific compounds or forms of compounds behave when exposed to other chemicals or environmental conditions.
1. A method of screening an array of samples comprising analyzing an array of samples with a system for detecting similarities among a plurality of samples, which comprises
a) a device for obtaining a spectrum for each sample; and
b) a computer configured to analyze each of the spectra and to generate a plurality of bins, wherein each bin corresponds to samples sharing at least one spectral feature.
2. The method of claim 1 wherein the spectral feature is unique to a particular form of a compound-of-interest.
3. The method of claim 1 , wherein the device is an infrared spectrometer, near infrared spectrometer, NMR spectrometer, X-ray diffractometer, neutron diffractometer, light microscope, electron microscope, second harmonic generator, circular dichroism spectrometer, linear dichroism spectrometer, differential scanning calorimeter, thermal gravimetric analyzer, or melting point analyzer.
4. The system of claim 1 wherein the device is a Raman spectrometer.
5. The system of claim 1 wherein the computer is further configured to generate a binary spectral representation for a spectrum that reflects the presence or absence of a spectral feature.
6. The system of claim 1 wherein the computer is configured to mutually compare a plurality of spectra and generate a hierarchical clustering dendrogram.
7. The system of claim 1 wherein the computer is configured to cluster the plurality of spectra.
8. The system of claim 7 wherein the computer is configured to cluster the plurality of spectra in accordance with iterative k-means clustering.
9. The system of claim 1 wherein the computer is configured to cluster the plurality of spectra such that if a majority of spectra obtained from a single sample are assigned to a particular bin, then all spectra from that sample are assigned to that bin.
10. The system of claim 1 wherein the computer is configured to assign newly obtained spectra to at least one of the plurality of bins.
11. The system of claim 1 wherein the computer is configured to modify, in response to an analysis of newly obtained spectra, at least one of the plurality of bins.
12. The system of claim 1 wherein the computer is configured to add, in response to an analysis of newly obtained spectra, at least one bin to the plurality of bins.
13. The system of claim 1 wherein the computer is configured to generate a similarity matrix representing the similarity between at least two of the plurality of samples.
14. The system of claim 13 wherein the computer is further configured to sort the samples such that they are arranged to reflect their similarity.
15. The system of claim 13 wherein the computer is further configured to sort the similarity matrix such that a diagonal in the matrix represents samples exhibiting the greatest similarity.
16. The method of claim 1 wherein the samples comprise a solid form compound of interest.
17. The method of claim 2 wherein the particular form is a solid form.
18. The method of claim 16 wherein the solid form is a crystalline form.
19. The method of claim 16 wherein the solid form is an amorphous form.
20. The method of claim 16 the particular form is a hydrate.
21. The method of claim 17 wherein the solid form is a crystalline form.
22. The method of claim 17 wherein the solid form is an amorphous form.
23. The method of claim 17 the particular form is a hydrate.