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.
Extract The first step in the ETL process is extracting the data from various sources. Each of the source systems may store its data in completely different format from the rest. The sources are usually flat files or RDBMS, but almost any data storage can be used as a source for an ETL process.