Fluid exit in reaction chambers

An apparatus for synthesizing a plurality of biopolymers on a support in the form of an array, said apparatus comprising:

• (a) a chamber,
• (b) a gas inlet for introducing a gas into the interior of said chamber,
• (c) a device for dispensing reagents for synthesizing said biopolymers in the form of an array, said device being in fluid communication with said chamber, and
• (d) an opening in said chamber for exit of said gas, wherein at least one wall of said opening is designed to provide a contracting section, a section having substantially constant cross-sectional area and a diffusing section through said opening.

An apparatus for synthesizing an array of biopolymers on a support, said apparatus comprising:

• (a) a chamber,
• (b) a gas inlet for introducing a gas into the interior of said chamber,
• (c) a device for dispensing reagents for synthesizing said biopolymers, said device being in fluid communication with said chamber,
• (d) an opening for exit of said gas, said opening comprising a pair of side walls, wherein at least one of said side walls is designed such that said opening comprises a contracting section, a section having substantially constant cross-sectional area and a diffusing section, wherein contraction in said contracting section takes place over a region from about 0.15 to about 2 times the width of said section having substantially constant cross-sectional area and wherein said diffusing section expands at a rate of about 0.08 to about 0.18 cm/cm and
• (e) a mechanism for moving said support into and out of said chamber through said opening and for positioning said support relative to said device for dispensing reagents, wherein said mechanism comprises a holding element for said support wherein said holding element is a low drag body having Reynolds numbers that are less than about 3000.

A method for synthesizing a plurality of biopolymers on a support in the form of an array, said method comprising:

• (a) introducing a support into a reaction chamber wherein said reaction chamber has a positive and substantially uniform unidirectional flow of gas therethrough wherein discrete sites on the surface of said support are activated and wherein said gas exits said reaction chamber through a gas outlet in a direction that is the same as said unidirectional flow wherein in said gas outlet said gas flow is first contracted and then diffused,
• (b) bringing said support and a dispensing system for dispensing reagents for the synthesis of said biopolymers into a dispensing position relative to said activated discrete sites on said surface,
• (c) dispensing said reagents to said discrete sites,
• (d) removing said support and/or said dispensing system from said relative dispensing position, and
• (e) optionally repeating steps (a) through (d) until said biopolymer is formed.