We are pleased to provide downloads, or links, to a number of papers on flow cytometry which were produced using Vertilon's PhotoniQ DAQs.
Gèrald Grègori, Valery Patsekin, Bartek Rajwa, James Jones, Kathy Ragheb, Cheryl Holdman, J. Paul Robinson
Cytometry Part A, Volume 81A, Issue 1, pages 35-44, January 2012
Copyright ©2011 International Society for Advancement of Cytometry
Despite recent progress in cell-analysis technology, rapid classification of cells remains a very difficult task. Among the techniques available, flow cytometry (FCM) is considered especially powerful, because it is able to perform multiparametric analyses of single biological particles at a high flow rate-up to several thousand particles per second. Moreover, FCM is nondestructive, and flow cytometric analysis can be performed on live cells. The current limit for simultaneously detectable fluorescence signals in FCM is around 8-15 depending upon the instrument. Obtaining multiparametric measurements is a very complex task, and the necessity for fluorescence spectral overlap compensation creates a number of additional difficulties to solve. Further, to obtain well-separated single spectral bands a very complex set of optical filters is required. This study describes the key components and principles involved in building a next-generation flow cytometer based on a 32-channel PMT array detector, a phase-volume holographic grating, and a fast electronic board. The system is capable of full-spectral data collection and spectral analysis at the single-cell level. As demonstrated using fluorescent microspheres and lymphocytes labeled with a cocktail of antibodies (CD45/FITC, CD4/PE, CD8/ECD, and CD3/Cy5), the presented technology is able to simultaneously collect 32 narrow bands of fluorescence from single particles flowing across the laser beam in <5 µs. These 32 discrete values provide a proxy of the full fluorescence emission spectrum for each single particle (cell). Advanced statistical analysis has then been performed to separate the various clusters of lymphocytes. The average spectrum computed for each cluster has been used to characterize the corresponding combination of antibodies, and thus identify the various lymphocytes subsets. The powerful data-collection capabilities of this flow cytometer open up significant opportunities for advanced analytical approaches, including spectral unmixing and unsupervised or supervised classification.
Gregory Goddard, John C. Martin, Mark Naivar, Peter M. Goodwin, Steven W. Graves, Robb Habbersett, John P. Nolan, James H. Jett,
National Flow Cytometry Resource, Bioscience Division, Los Alamos National Laboratory, Cytometry Part A 69A:842–851
Copyright ©2006 International Society for Analytical Cytology
While conventional multi-parameter flow cytometers have proven highly successful, there are several types of analytical measurements that would benefit from a more comprehensive and flexible approach to spectral analysis including, but certainly not limited to spectral deconvolution of overlapping emission spectra, fluorescence resonance energy transfer measurements, metachromic dye analysis, free versus bound dye resolution, and Raman spectroscopy. The described system utilizes a diffraction grating to disperse the collected fluorescence and side-scattered light from cells or microspheres passing through the interrogation region over a rectangular charge-coupled-device image sensor. The flow cell and collection optics are taken from a conventional flow cytometer with minimal modifications to assure modularity of the system.
J. Paul Robinson, Bartek Rajwa, Gerald Gregori, James Jones, Valery Patsekin
Proceedings of SPIE Vol. 5692
Detecting biological particles and subsequently identifying them in a very short period of time is highly desirable, but a very difficult task. There are several pathways for developing rapid detection systems. For example, one can reduce sample size to a very small volume, and amplify cellular components by PCR technology with a view to identifying antigen-specific molecules. Alternatively, antibody-based assays allow for detection and identification of a variety of well-characterized pathogens. The system proposed utilizes flow cytometry technology to rapidly detect spectral fingerprints or organisms. However, the current limit for simultaneously detectable fluorescence signals in flow cytometry is around 12-15. Making these measurements is very complex and the necessity for advanced spectral overlap calculations creates a number of difficult problems to solve in a short period of time. Next-generation instruments can either increase the number of detectors or modify the principles of collection. If the detector system were simplified, the overall cost and complexity of single-cell analytical systems might be reduced. This requires changes in both hardware and software that allow for the analysis of 30 or more spectral signals. Further, analysis of complex data sets requires some completely new approaches, particularly in the area of multispectral analysis. This paper describes the key components and principles involved in building a next-generation instrument which can collect simultaneously 32 bands of fluorescence from a particle in less than 5 microseconds. This would allow the analysis of several thousand bioparticles per second. The flow cytometry system based on our new detector would be designed to be portable and low cost.