Abstract: A sample presentation apparatus comprises a round support movable in an optical assembly and having a flange region and an elevated gear shaped region having indexing gear cogs at intermediate radius locations of the support; a sample carrier slide holder removably supported on and movable with the support, the slide holder having at least one arm extending radially from a central hub of the sample carrier slide holder and being aligned between a first pair of indexing gear cogs; and at least one sample carrier slide removably supported on the support and aligned by the first pair of indexing gear cogs. In another embodiment of the invention, a self-aligning movable platform and support apparatus in an optical assembly comprises coarse and fine alignment mechanisms.

Abstract: The invention provides a method of calibrating measurement device using a Raman-active composition, wherein the composition is active, in one embodiment, in a wavelength region that ranges from about 300 nm to about 1200 nm, and in another embodiment, from about 550 nm to about 650 nm. The method is especially useful in the calibration of fluorescent measurement devices. The method of the invention provides several advantages, such as, in facile identification of problems with the device when it occurs, in not having to tune and adjust the device very often, and neutralizing variations between different runs and different instruments. In another aspect, the invention also provides a device that is calibrated using the method of the invention. In one embodiment, the Raman-active composition useful in the invention is a derivative of 1,4-bis(2-methyl-styryl)-benzene.