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 process of extracting data from source systems and bringing it into the data warehouse is commonly called ETL, which stands for extraction, transformation, and loading. Note that ETL refers to a broad process, and not three well-defined steps.