Abstract: A sample preparation instrument with an integrated device for estimating a concentration of white blood cells in a specimen is described. The sample preparation instrument receives a specimen for which a sample is to be prepared for analysis. The integrated device can implement an optical method, an electrical resistance method, or a flow cytometry method, for example, to estimate the white blood cell concentration in the specimen. For some types of analysis, a sample volume of the specimen is dependent on the white blood cell concentration. Therefore, the sample preparation instrument can automatically determine and adjust the sample volume of the specimen based on the estimated white blood cell concentration prior to adding additional reagents, such as labeling reagents and/or lytic reagents, to prepare the sample.

Abstract: A flow cytometer sorting mechanism is operative to controllably sort successively generated fluid droplets in accordance with the contents of a plurality of contiguous precursor regions of the carrier fluid which are contained within a target droplet of interest and precursor regions for droplets on either side of the target droplet. This multi-region sorting window scheme is particularly useful in reducing the time required to harvest a highly purified quantity of a particular type of cell, as not only are droplets containing only desired cells sorted to a highly purified collection store, but should an undesired cell be detected within a predefined proximity of a desired cell, rather than being simply aborted, the droplet is sorted into an auxiliary enrichment container, whose contents may then be reclaimed for resorting. Since all droplets are sorted to one of a plurality of droplet reclamation containers, substantially no detected/target cells are lost.