Blood counting machines aspirate a very small amount of the specimen through narrow tubing followed by an aperture and a laser flow cell. Laser eye sensors count the number of cells passing through the aperature, and can identify them; this is flow cytometry.
In computing, Extract, Transform and Load (ETL) refers to a process in database usage and especially in data warehousing that performs: Data extraction â extracts data from homogeneous or heterogeneous data sources.
The first part of an ETL process involves extracting the data from the source system(s). In many cases this represents the most important aspect of ETL, since extracting data correctly sets the stage for the success of subsequent processes.