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.
ETL development is a subset of database development that focuses on the pipeline/tools used to extract data from a data source, transform it into something useful, and load it into a database (or other data store).