Patent ID: 9606043
Date: 2017-03-28
CPC Classifications: G01N

Claim:
1. A method, comprising: flowing a liquid sample past an interrogation zone of a flow cell in a flow cytometer; irradiating the interrogation zone with a light beam, wherein the light beam is manipulated by beam shaping optics positioned between the light source and the flow cell to create a horizontally flat beam profile that irradiates the liquid sample at the interrogation zone; blocking, using a mask disposed in an optical path between the flow cell and an intermediate angle scatter (IAS) light detector of the flow cytometer, a horizontal diffraction pattern created by the flat beam profile irradiating the liquid sample while allowing all intermediate angle scatter emitted from the liquid sample to be detected by the IAS light detector, wherein the mask comprises a central hole that is positioned to allow one or more axial light loss (ALL) measurements through the central hole; and measuring the intermediate angle scatter emitted from the liquid sample using the IAS detector.