초록 ▼

A position of a piston fluid-tightly sliding along an inner surface of a pipette is instantaneously changed by a short distance to jet a portion of a liquid in the pipette through the nozzle of the pipette as a drop. The instantaneously changed position is provided by a motor which is commonly used

A position of a piston fluid-tightly sliding along an inner surface of a pipette is instantaneously changed by a short distance to jet a portion of a liquid in the pipette through the nozzle of the pipette as a drop. The instantaneously changed position is provided by a motor which is commonly used for moderately changing the position of the piston to taking-in and taking-out the liquid. The instantaneous minute position changing may be provided with a piezoelectric actuator. An attachable nozzle cap having a nozzle-cap nozzle (through hole) of which diameter is smaller than that of the nozzle of the pipette may be used. The portion of the liquid jetted from the pipette may be detected. The instantaneous changing may be repeated to jet a desired amount of said liquid. The short distance may be adjusted in accordance with the desired amount.

대표청구항 ▼

1. A pipetting apparatus comprising:a pipette having a nozzle;pipette holding means for holding said pipette;a piston fluid-tightly sliding along an inner wall of said pipette, a fluid receiving inner space being defined by said inner wall of said pipette, the nozzle and a lower portion of said pist

1. A pipetting apparatus comprising:a pipette having a nozzle;pipette holding means for holding said pipette;a piston fluid-tightly sliding along an inner wall of said pipette, a fluid receiving inner space being defined by said inner wall of said pipette, the nozzle and a lower portion of said piston, and varying in size as said piston slides along the inner wall of said pipette;piston holding means for holding a portion of said piston; andposition changing means including a means for varying a sliding speed of said piston, wherein said means for varying said sliding speed is an actuator for changing a position of said piston with said piston holding means to suck a liquid into said pipette at a first speed and for changing said position of said piston with said piston holding means by a short distance with respect to said pipette holding means at a second speed higher than said first speed to jet a portion of said liquid in said pipette through said nozzle as a drop, wherein said short distance is determined in accordance with a desired amount of said jetted portion of said liquid. 2. A pipetting apparatus as claimed in claim 1, wherein said actuator comprises a motor, said pipetting apparatus further comprises another position changing means including said motor for changing said position of said piston with said motor in response to a low speed signal to suck and discharge a desired amount of said liquid, and said motor is commonly used between said position charging means and said another position changing means. 3. A pipetting apparatus as claimed in claim 1, wherein said position changing means comprises a piezoelectric actuator. 4. A pipetting apparatus as claimed in claim 1, further comprising an attachable nozzle cap being attachable to said pipette and having a nozzle-cap nozzle for jetting said portion of said liquid through said nozzle and said nozzle-cap nozzle, a diameter of said nozzle-cap nozzle being smaller than that of said nozzle. 5. A pipetting apparatus as claimed in claim 1, further comprises:detection means for detecting said portion of said liquid jetted from said pipette; andconfirming means in response to said position changing means and said detection means for confirming that said portion of said liquid is jetted and outputting a confirmed result. 6. A pipetting apparatus as claimed in claim 1, wherein said liquid is sucked into said inner space defined by said pipette and said piston in accordance with said position of said piston. 7. A pipetting apparatus as claimed in claim 1, wherein a position at which said piston fluid-tightly slides along said inner wall of said pipette is movable to said pipette along said inner surface. 8. A pipetting apparatus as claimed in claim 1, wherein said first speed is sufficiently low to prevent formation of a space between said piston and said inner wall of said pipette while said piston slides along the inner wall to suck liquid into said pipette, for preventing air from entering said fluid receiving inner space through said space therebetween. 9. A pipetting apparatus as claimed in claim 1, further comprising supporting means for supporting said pipette holding means, said piston holding means, and said position changing means. 10. A pipetting apparatus as claimed in claim 9, wherein said supporting means is capable of being hand-held. 11. A pipetting apparatus as claimed in claim 9, wherein said supporting means is capable of being hand-held by a robot arm. 12. A pipetting apparatus as claimed in claim 1, wherein said pipette is replaceable with said pipette holding means, and said piston is replaceable with said piston holding means. 13. A pipetting apparatus comprising:a pipette having a nozzle;pipette holding means for holding said pipette;a piston fluid-tightly sliding along an inner wall of said pipette, an inner space defined by said pipette and said piston being directly coupled to said nozzle;position holding means for holding a portion of said pist on; andposition changing means including a means for varying a pulse rate of said pistol, wherein said means for varying said pulse rate is a linear pulse motor for changing a position of said piston with said piston holding means in response to a pulse signal at a first pulse rate to suck said liquid into said pipette and for changing said position of said piston with said piston holding means by a short distance with respect to said pipette holding means in response to said pulse signal at a second pulse rate to jet a portion of a liquid in said pipette through said nozzle as a drop, wherein said second pulse rate is higher than said first rate, and wherein said short distance is determined in accordance with a desired amount of said jetted portion of said liquid. 14. A pipetting apparatus as claimed in claim 13, further comprising an attachable nozzle cap being attachable to said pipette and having a nozzle-cap nozzle for jetting said portion of said liquid through said nozzle and said nozzle-cap nozzle, a diameter of said nozzle-cap nozzle being smaller than that of said nozzle. 15. A pipetting apparatus as claimed in claim 13, further comprises;detection means for detecting said portion of said liquid jetted from said pipette; andconfirming means in response to said position changing means and said detection means for confirming that said portion of said liquid is jetted and outputting a confirmed result. 16. A pipetting apparatus as claimed in claim 13, wherein said liquid is sucked into said inner space defined by said pipette and said piston in accordance with said position of said piston. 17. A pipetting apparatus as claimed in claim 13, wherein a position that said piston fluid-tightly slides along said inner wall of said pipette is movable to said pipette along said inner surface. 18. A pipetting apparatus as claimed in claim 13, wherein said first speed is sufficiently low to prevent formation of a space between said piston and said inner wall of said pipette while said piston slides along the inner wall to suck liquid into said pipette, for preventing air from entering said fluid receiving inner space through said space therebetween. 19. A pipetting apparatus as claimed in claim 13, further comprising supporting means for supporting said pipette holding means, said piston holding means, and said position changing means. 20. A pipetting apparatus as claimed in claim 13, wherein said supporting means is capable of being hand-held. 21. A pipetting apparatus as claimed in claim 13, wherein said supporting means is capable of being hand-held by a robot arm. 22. A pipetting apparatus as claimed in claim 13, wherein said pipette is replaceable with said pipette holding means, and said piston is replaceable with said piston holding means. 23. A method of pipetting a liquid with a pipetting apparatus comprising: a pipette having a nozzle;pipette holding means for holding said pipette;a piston fluid-tightly sliding along an inner wall of said pipette, a fluid receiving inner space being defined by said inner wall of said pipette, the nozzle and a lower portion of said piston, and varying in size said piston slides along the inner wall of said pipette;piston holding means for holding a portion of said piston;position changing means including a means for varying a sliding speed of said piston, wherein said means for varying said sliding speed is an actuator for changing a position of said piston with said piston holding means to suck a liquid into pipette at a first speed and for changing said position of said piston with said piston holding means by a short distance with respect to said pipette holding means at a second speed higher than said first speed to jet a portion of said liquid in said pipette through said nozzle as a drop, andan attachable nozzle cap being attachable to said pipette and having a nozzle-cap nozzle for jetting said portion of said liquid through said nozzle and said nozzle-cap nozzle, a diameter of sa id nozzle-cap nozzle being smaller than that of said nozzle, wherein said short distance is determined in accordance with a desired amount of said jetted portion of said liquid, said method comprising the steps of:sucking said liquid into said pipette with said position changing means through said nozzle without said attachable nozzle;attaching said attachable nozzle having said nozzle-cap nozzle to jet said portion of said liquid through said nozzle and said nozzle-cap nozzle; andoperating said position changing means to jet a portion of said liquid in said pipette through said nozzle and said nozzle-cap nozzle as a drop. 24. A pipetting apparatus comprising:a pipette having a nozzle;pipette holding means for holding said pipette;a piston fluid-tightly sliding along an inner wall of said pipette, a fluid receiving inner space being defined by said inner wall of said pipette, the nozzle and a lower portion of said piston, and varying in size as said piston slides along the inner wall of said pipette;piston holding means for holding a portion of said piston; andposition changing means including a means for varying a sliding speed of said piston, wherein said means for varying said sliding speed is an actuator for changing a position of said piston with said piston holding means to suck a liquid into said pipette at a first speed whereby a space is prevented from being formed between the inner wall of said pipette and a sliding surface of said piston which is to be kept in fluid-tight contact with the inner wall of said pipette and for changing said position of said piston with said piston holding means by a short distance with respect to said pipette holding means at a second speed higher than said first speed to jet a portion of said liquid in said pipette through said nozzle as a drop, wherein said short distance is determined in accordance with a desired amount of said jetted portion of said liquid. 25. A pipetting apparatus as claimed in claim 24, whereinsaid liquid is sucked into said inner space defined by said pipette and said piston in accordance with said position of said piston,a position at which said piston fluid-tightly slides along said inner wall of said pipette is movable to said pipette along said inner surface, andsaid first speed is sufficiently low to prevent the air from entering said inner space through a space which would be made between said piston and said inner wall of said pipette while said liquid is sucked into said pipette,said pipetting apparatus further comprising:supporting means for supporting said pipette holding means, said piston holding means, and said position changing means, whereinsaid supporting means is capable of being hand-held, wherein said pipette is replaceable with said pipette holding means, and said piston is replaceable with said piston holding means.