Efficient haploid cell sorting flow cytometer systems

Abstract

A flow cytometry system (1) for sorting haploid cells, specifically irradiatable sperm cells, with an intermittingly punctuated radiation emitter (56). Embodiments include a beam manipulator (21) and even split radiation beams directed to multiple nozzles (5). Differentiation of sperm characteristics with increased resolution may efficiently allow differentiated sperm cells to be separated higher speeds and even into subpopulations having higher purity.

Description

I. FIELD OF THE INVENTION [0001] The present invention relates to a flow system for particle analysis. More specifically, the invention relates to the use of a pulsed laser on a flow system for particle analysis which results in more accurate quantification of measurable properties of individual particles. It may be of particular interest in analyzing populations of very similar particles, at high speeds, allowing more efficient separation of particles into two or more different populations. The invention is particularly useful in the application of separating live X-chromosome bearing and Y-chromosome bearing sperm of all mammals at higher speeds, better purities and with equal or better sperm health outcomes, meaning less damage to sperm. The invention may contribute significant improvements to the economics of sperm sorting. II. BACKGROUND OF THE INVENTION [0002] Lasers can be used to deliver light to biological or non-biological particles and emission spectra can be used for the...

AI Technical Summary

Benefits of technology

[0026] Accordingly, a broad object of the invention may provide a particle analysis system having a pulsed laser which can be operated at a low power.

[0028] Yet another broad object of the invention can be to provide a particle analysis system having a pulsed laser which allows differentiated particles to be separated into subpopulations having a higher incidence of the desired characteristic.

[0032] Another broad object of the invention can be to provide a particle analysis system having a pulsed laser which allows differentiated particles to be separated into subpopulations at a greater rate than conventional particle analysis systems using a CW laser.

[0033] Another broad object of the invention can be to provide a particle analysis system having a pulsed laser which allows sperm cells of any species of mammal to be differentiated with increased resolution into X-chromosome or Y-chromosome bearing subpopulations. The benefits of this object of the invention may allow differentiation of sperm cells having: less DNA bound fluorochrome, less residence time in staining protocols, greater elapsed storage time prior to sorting, or perhaps even less affinity to stain due to having been frozen prior to staining protocols.

[0035] Yet another broad object of the invention can be to provide a miniaturized and parallel flow cytometer which allows a multiple of nozzles sorting in tandem to be positioned on the same apparatus, that may allow increases in the production rate of sorting, by increasing the number of nozzles which are sorting on a single apparatus.

Problems solved by technology

Such light may also be affected by filters which may reduce the net energy of the beam.

However, in some instances, CW lasers can have particular disadvantages for applications as discussed here.

The beam can result in modification or destruction of the sample being observed.

For example, with respect to sperm cells, irradiation can result in lower fertility of the sperm cells.

This disclosure may teach the disadvantages of a laser diode apparatus.

Factors which can contribute to inaccurate measurements of single particles may include the saturation of a stain or even a conjugate to a particle, variation in the quanta of illumination light, effects from the shape of a particle, and perhaps even electronic noise in the detection apparatus.

An example of a particularly challenging problem is the sorting of X-chromosome bearing and Y-chromosome bearing sperm of mammals at high processing rates and high sorting purities.

There may be, however, a distinct problem in that at rates faster than 2500 per second, the purity of the sample may decrease.

Yet, there may be problems associated with an increase of intensity or perhaps even an increase of power with a continuous wave laser.

Ionizing may then cause changes to the DNA.

Another problem may include the energy that it may take to power a continuous laser to deliver about 150 mW of energy at near UV spectrum.

Furthermore, a tube life of ion lasers may be reduced when operating at higher powers.

An additional problem with the use of continuous wave lasers may be that the CV may drop significantly when using lower powers such as between about 20-80 mW.

Yet, a major problem facing the development of reliable flow analysis and flow sorting in parallel may be the high intensity of laser light needed for analysis at each nozzle.

There may be certain industrial uses of flow cytometers, as preparative instruments, which may be economically limited by the traditional methods of processing.

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