Parameters for use in particle discrimination
Aspects of the present disclosure include methods for characterizing particles of a sample in a flow stream. Methods according to certain embodiments include detecting light from a sample having cells in a flow stream, generating an image of an object in the flow stream in an interrogation region and determining whether the object in the flow stream is an aggregate based on the generated image. Systems having a processor with memory operably coupled to the processor having instructions stored thereon, which when executed by the processor, cause the processor to generate an image of an object in a flow stream and to determine whether the object is an aggregate are also described. Integrated circuit devices (e.g., field programmable gate arrays) having programming for practicing the subject methods are also provided.
1. A method for determining whether an object in a flow stream is a cell aggregate, the method comprising:
detecting light from a sample comprising cells in a flow stream;
generating frequency-encoded data of an object in the flow stream in an interrogation region to obtain spatial data comprising spatially encoded frequencies across the object; and
determining whether the object in the flow stream is a cell aggregate based on the spatial data.
2. The method according to claim 1 , wherein detecting light from the sample in the flow stream comprises detecting light scatter from the sample in the flow stream.
3. The method according to claim 2 , wherein the method comprises detecting forward scattered light from the sample in the flow stream.
4. The method according to claim 2 , wherein the method comprises detecting side scattered light from the sample in the flow stream.
5. The method according to claim 1 , further comprising determining the size of the object based on the spatial data.
6. The method according to claim 1 , further comprising determining the center of mass of the object based on the spatial data.
7. The method according to claim 1 , further comprising determining the eccentricity of the object based on the spatial data.
8. The method according to claim 1 , further comprising calculating an image moment of the object based on the spatial data.
9. The method according to claim 8 , wherein the method comprises calculating a first order image moment of the object along a horizontal axis.
10. The method according to claim 8 , wherein the method comprises calculating a second order image moment of the object along a horizontal axis.
11. The method according to claim 8 , wherein the method comprises calculating a first order image moment of the object along a vertical axis.
12. The method according to claim 8 , wherein the method comprises calculating a second order image moment of the object along a vertical axis.
13. The method according to claim 12 , wherein generating an image of the object in the interrogation region comprises generating an image mask of the object.
14. The method according to claim 13 , wherein generating an image mask comprises:
generating a greyscale image of the object in the flow stream;
determining a pixel intensity threshold value from the greyscale image;
comparing each pixel from the greyscale image against the determined threshold value; and
converting each pixel to a binary pixel value.
15. The method according to claim 14 , wherein the image mask comprises pixels having a pixel value of 1.
16. The method according to claim 14 , further comprising determining one or more of: the size of the object based on the generated image mask; the center of mass of the object based on the generated image mask and the eccentricity of the object based on the generated image mask.
17. The method according to claim 1 , further comprising generating an image of the object from the spatial data.
18. A system comprising:
a light source configured to irradiate a sample comprising cells in a flow stream;
a light detection system comprising a photodetector; and
a processor comprising memory operably coupled to the processor wherein the memory comprises instructions stored thereon, which when executed by the processor, cause the processor to:
generate frequency-encoded data of an object in the flow stream in an interrogation region to produce spatial data comprising spatially encoded frequencies across the object; and
determine whether the object in the flow stream is a cell aggregate based on the spatial data.
19. The system according to claim 18 , wherein the light detection system comprises a photodetector configured to detect light scatter from the sample in the flow stream.
20. An integrated circuit programmed to:
generate frequency encoded data of an object in the flow stream in an interrogation region to produce spatial data comprising spatially encoded frequencies across the object; and
determine whether the object in the flow stream is a cell aggregate based on the spatial data.