Microvolume-liquid dispensing method and microvolume-liquid dispenser

A microvolume-liquid dispenser for dispensing a nanoliter-quantity to picoliter-quantity microvolume liquid from a tip-end opening in a tubular nozzle,

• the microvolume-liquid dispenser comprising:
• a liquid passage having an upstream-side passage section, an intermediate passage section, and a downstream-side passage section, the intermediate passage section being capable of expanding and contracting so as to increase or decrease in interior volume;
• a liquid supply part for supplying liquid to the nozzle via the liquid passage;
• a passage-deforming mechanism for deforming the intermediate passage section so as to increase or decrease the interior volume of the intermediate passage section;
• and
• a control unit;
• in a case in which the intermediate passage section is deformed such that the interior volume thereof is reduced while a liquid-filled state is attained in which the liquid fills a portion from the liquid passage to the tip-end opening of the nozzle, a ratio of an amount of liquid pushed out from the intermediate passage section to the downstream-side passage section and an amount of liquid pushed back to the upstream-side passage section being set to 1:100-1:500 so that the amount of pushed-out liquid reaches a very small amount;
• i.e., nanoliter quantities or picoliter quantities;
• the control unit carrying out a microvolume liquid dispensing operation for controlling the passage-deforming mechanism so as to deform the intermediate passage section such that the interior volume thereof is reduced while the liquid-filled state is attained, and causing the microvolume liquid to be dispensed from the tip-end opening of the nozzle due to the very small amount of liquid being pushed out from the intermediate passage section to the downstream-side passage section;
• and
• the control unit furthermore carrying out a recovery operation for controlling the passage-deforming mechanism so as to stop the deformation of the intermediate passage section to return the interior volume of the intermediate passage section to an original volume, draw a very small amount of liquid back into the intermediate passage section from the downstream-side passage section, and draw liquid into the intermediate passage section from the upstream-side passage section.