Micro-globule metering and sampling structure and microchips having the structure

摘要

An improved structure has a first channel and a second channel that extend in specified directions, a third channel open in a wall of said first channel and a fourth channel that is open to a wall of said second channel such that it couples an end of said third channel to said second channel, that has a property of being less wettable (or insensitive to capillary attraction) and that is narrower than the other three channels; a liquid introduced into said first channel is drawn into said third channel and thereafter said liquid that remains in said first channel is removed to meter and sample a volume of globule equal to the capacity of said third channel. If the second channel is already filled with a liquid, the structure is modified to further include a fifth channel that is open to a wall of said fourth channel, that is narrower than or equal in thickness to said fourth channel and that is made of a wall having a property of being less wettable (or insensitive to capillary attraction) . <IMAGE>