Method and system incorporating beam shaping optics and beam stabilization

Abstract

This disclosure pertains to analytical instruments and related methods incorporating beam shaping optics for differentiating very bright and closely related signals over a wide range of operating conditions with an improved and uniform performance.

What is claimed is: 
     
         1 . An analytical instrument for sperm comprising:
 a flow channel that receives a sheath fluid and a sample fluid having at least one sperm to be analyzed and that creates a coaxial flow of a fluid stream having an inner core stream of the sample fluid and an outer stream of the sheath fluid, wherein the inner core stream comprises an elliptical shape with a minor axis and a major axis, wherein the major axis comprises an inner core stream width between 24 and 40 microns;   a laser that produces a laser beam;   beam shaping optics that shape the laser beam to have a beam width and a beam height at an interrogation location, wherein between a center half and a center quarter of the beam width overlaps the inner core stream width facing the laser;   a beam path along which the laser beam traverses between the laser and the beam shaping optics;   at least one detector that generates a signal in response to electromagnetic radiation from the interrogation location; and   an analyzer that receives the signal from the at least one detector.   
     
     
         2 . The analytical instrument of  claim 1 , wherein the inner core stream minor axis comprises an inner core stream depth. 
     
     
         3 . The analytical instrument of  claim 1 , wherein a beam width to beam height ratio is: between about 7:1 and about 3:1; between about 6:1 and about 4:1; between about 7:1 and about 6:1; between about 6:1 and about 5:1; between about 5:1 and about 4:1; or between about 4:1 and about 3:1. 
     
     
         4 . The analytical instrument of  claim 1 , wherein the beam shaping optics shape the laser beam to a beam width that is in a range of about 70 μm to about 90 μm, about 90 μm to about 110 μm, or about 110 μm to about 130 μm. 
     
     
         5 . The analytical instrument of  claim 1 , further comprising:
 a plurality of additional flow channels, each additional flow channel creating an additional coaxial flow of a fluid stream having an additional elliptical inner core stream of the sample fluid and an additional outer stream of the sheath fluid;   an additional laser associated with each additional flow channel that produces an additional laser beam;   additional beam shaping optics associated with each additional flow channel that shape each additional laser beam to have a center portion of a beam width that substantially matches a width of the additional inner core stream facing the additional laser with which the additional beam shaping optics are associated; and   an additional beam path between each additional laser and each associated beam shaping optics,   wherein each additional beam path has a length that is less than 18 inches.   
     
     
         6 . The analytical instrument of  claims 1 , wherein the beam path is less than 18 inches. 
     
     
         7 . The analytical instrument of  claim 1 , wherein the beam shaping optics shape the laser beam to a beam height that is in a range of 15 μm to 19 μm. 
     
     
         8 . The analytical instrument of  claim 1 , wherein the analytical instrument further comprises a skewing element that generates a population of sperm having a skewed sex ratio of viable sperm. 
     
     
         9 . The analytical instrument of  claim 8 , wherein the skewing element comprises deflection plates in a droplet generating flow cytometer, or an ablation laser that damages selected sperm based on their classification. 
     
     
         10 . The analytical instrument of  claim 1 , wherein the beam width to beam height ratio is: between about 7:1 and about 3:1; between about 6:1 and about 4:1; between about 7:1 and about 6:1; between about 6:1 and about 5:1; between about 5:1 and about 4:1; or between about 4:1 and about 3:1. 
     
     
         11 . A method of generating a population of sperm having a skewed sex ratio of viable sperm, comprising:
 creating a coaxial flow of a fluid stream comprising:
 an inner core stream of a sample fluid, wherein the inner core stream comprises an elliptical shape with a minor axis and a major axis, wherein the major axis comprises an inner core stream width between 24 and 40 microns; and 
 an outer stream of a sheath fluid; 
   modifying a laser beam into a laser beam pattern having a beam width in a range where no more than a center half of the beam width overlaps the inner core stream width;   interrogating the sperm in the core stream with the laser beam pattern;   detecting a response to the interrogation of the sperm;   generating at least one signal based on the detected response; and   classifying a sex differentiation characteristic of the sperm based on the at least one signal.   
     
     
         12 . The method of  claim 11 , wherein the inner core stream minor axis further comprises an inner core stream depth. 
     
     
         13 . The method of  claim 11 , wherein the beam width to beam height ratio is: between about 7:1 and about 3:1, between about 6:1 and about 4:1; between about 7:1 and about 6:1; between about 6:1 and about 5:1; between about 5:1 and about 4:1; or between about 4:1 and about 3:1. 
     
     
         14 . The method of  claim 11 , wherein the beam width is in a range of about 70 μm to about 90 μm, about 90 μm to about 110 μm, or about 110 μm to about 130 μm. 
     
     
         15 . The method of  claim 11 , wherein the beam width is between about 1.5 and 4.5 times the length of the core stream width. 
     
     
         16 . The method of  claim 11 , further comprising:
 differentially collecting sperm based on the sex differentiation characteristic.   
     
     
         17 . The method of  claim 11 , further comprising:
 photo-ablating sperm based on the sex differentiation characteristic.   
     
     
         18 . The method of  claim 11 , wherein a volume of nuclear DNA within a head of the sperm is stained with a DNA selective light emission material, and wherein the DNA selective light emission material emits light in response to the interrogating step. 
     
     
         19 . The method of  claim 18 , further comprising:
 detecting a forward fluorescence of the DNA selective light emission material;   detecting a side fluorescence of the DNA selective light emission material; and   analyzing the forward fluorescence and the side fluorescence to determine the sex differentiation characteristic of the sperm.   
     
     
         20 . The method of  claim 11 , wherein the beam height is in a range of about 15 μm to 19 μm.