downstream

The region extending in a 3' direction from a gene.

1. With respect to DNA, the nucleotides that lie in the 3' direction from the point of reference, which is frequently the site at which transcription is initiated. This is generally designated +1, with downstream nucleotides numbered +2, +10 etc. 2. In chemical engineering, those phases of a manufacturing process that follow the biotransformation stage. Usually refers to the recovery and purification of the product of a fermentation process. See: downstream processing.

In the same direction as a stream or other flow, or toward the direction in which the flow is moving.

In tracing, downstream is the direction along the arcs that is the same as the direction of flow. Direction of flow is determined by a user-defined convention. See also directed network.

In communications, the direction of transmission flow from the source toward the sink. 2. With respect to the flow of data in a communications path: at a specified point, the direction toward which data are received later than at the specified point.