CN112206842A

CN112206842A - Multichannel pipettor

Info

Publication number: CN112206842A
Application number: CN201910627820.6A
Authority: CN
Inventors: 林继伟; 王洪琦
Original assignee: Huada Qinglan Biotechnology Wuxi Co ltd
Current assignee: Huada Qinglan Biotechnology Wuxi Co ltd
Priority date: 2019-07-12
Filing date: 2019-07-12
Publication date: 2021-01-12

Abstract

The invention relates to a multichannel pipettor, which consists of a fixed channel seat, a plurality of detachable movable channel heads, a movable push rod and a shell, wherein the channel heads are connected with the channel seat in a threaded manner, each movable channel head consists of a pipettor suction head, a rubber ring and a suction head sleeve, the threads are positioned on the outer surface of the suction head sleeve and used for fixing the rubber ring and the pipettor suction head on the channel seat, the movable push rod consists of pistons, a piston seat and a connecting rod, the number of the pistons is the same as that of the movable channel heads, and the shell is used for supporting fixed parts and guiding the movable parts.

Description

Multichannel pipettor

Technical Field

The invention relates to a liquid transfer device, in particular to a multi-channel liquid transfer device.

Background

The liquid transfer device is a tool capable of transferring liquid quantitatively, and the basic operation is to quantitatively suck a certain volume of liquid, move the position and discharge the liquid, and the process is generally operated by one hand. Pipettes can be divided into different specifications such as 2 microliters, 10 microliters, 200 microliters, 1 milliliter, 5 milliliters, 50 milliliters and the like according to the maximum volume of liquid absorption. According to the liquid transfer volume is adjustable, it is divided into adjustable liquid transfer device and non-adjustable liquid transfer device. According to the power mode, the device can be divided into a manual pipettor and an electric pipettor, and can be divided into a single-channel pipettor and a multi-channel pipettor according to the quantity of one-time pipettes; the number of common multi-channel pipette channels is 8 and 12. These classifications were developed to meet different pipetting requirements.

The 8-channel pipettor and the 12-channel pipettor can simultaneously transfer a plurality of samples, so for some pipetting operations with higher requirements on flux, the pipetting efficiency can be greatly improved, for example, 960 microliter of liquid is equally divided into 96 parts, a single-channel pipettor is firstly divided into 8 parts, each part is 120 microliter, and then the 8-channel pipettor is used for transferring 11 times in a one-line mode, and the operation is saved by 80% in comparison with the operation of directly transferring 96. The spacing between adjacent lanes of a multi-lane pipette is typically 9 mm. This is the standard pitch of wells such as 96-well deep-well plate, 96-well elisa plate, 96-well PCR plate, etc. Higher throughput vessels are also 384-well and 768-well. The hole spacing is 4.5 mm and 2.25 mm, and the multi-channel pipettors can be used for parallel pipetting and only need to be arranged at certain intervals.

Some pipetting stations can transfer 96 liquid samples at a time, and in conjunction with automated equipment, can achieve automated or semi-automated high throughput pipetting operations. However, they have not gained much popularity due to their very expensive equipment and poor operational flexibility.

Disclosure of Invention

The invention relates to a 24, 48 or 96 channel pipette, which is simple to maintain and high in operation flexibility and can be used in occasions with high flux requirements.

The invention provides a multichannel pipettor, which is characterized in that: comprises a fixed channel seat, a plurality of detachable movable channel heads, a movable push rod and a shell. The movable channel head is connected with the channel seat through threads, and the tightness of each channel can be adjusted by adjusting the tightness of the threads. A movable channel head comprises a pipette suction head, a rubber ring and a suction head sleeve, wherein the threads are positioned on the outer surface of the suction head sleeve and used for fixing the rubber ring and the pipette suction head to the channel seat, and the rubber ring is used for ensuring the tightness of the channel. When the movable push rod moves up and down, the volume in the sealing cavities of the channels can be adjusted simultaneously to realize the functions of liquid suction and liquid discharge, and one push rod consists of pistons, a piston seat and a connecting rod which are the same as the movable channel heads in number. The housing is used for supporting the fixed part and guiding the action of the movable part.

In some embodiments, the fixed channel seat is a rectangular solid with a length of 10-15 cm, a width of 7-10 cm and a height of 1-2 cm, and has 4 or 8 rows of 8 or 12 channel holes on the top, each channel hole communicating with the upper and lower surfaces of the channel seat. Within the same row, the passage holes are arranged at equal intervals, wherein the intervals are 4.5 mm, 9 mm or 18 mm. The row-to-row spacing is also equal, with the row spacing being 4.5 mm, 9 mm, or 18 mm.

In some embodiments, the lower opening of the passage hole is surrounded by a circle of cylindrical recess, and the recess is internally provided with threads which can be matched with the threads of the movable passage head.

In some embodiments, the pipette tip is a commercial tip having a size of 10 microliters, 200 microliters, 1 milliliter, and the like. The inner surface of the suction head sleeve is matched with the outer surface of the suction head with the corresponding specification in size. The tip of the suction head protrudes from the lower opening of the suction head sleeve, the thick end of the suction head is in contact with the rubber ring, and the outer diameter of the rubber ring is close to that of the thick end of the suction head, so that the rubber ring can be flatly placed on the plane of the thick end of the suction head. The upper half part of the suction head sleeve is a sleeve with an upward opening, the inner diameter of the sleeve is slightly larger than the thick end of the suction head, and the outer surface or the inner surface of the sleeve is provided with threads which are matched with the threads on the channel seat. The shape of the rubber ring can be changed by adjusting the tightness of the thread of the suction head sleeve and the channel seat, so that the inner diameter of the rubber ring is changed, and the tightness of the contact surface between the rubber ring and the suction head is changed.

In some embodiments, the diameter of the piston is the same as or slightly smaller than the inner diameter of the rubber ring. When the bottom of piston got into the rubber ring, can block up the hole of rubber ring to constitute a only sealed chamber of tip export of suction head between piston, rubber ring and suction head, its leakproofness comprises two parts: 1) the contact surface between the piston and the rubber ring, 2) the joint surface between the rubber ring and the thick end of the suction head; both of which are determined by the tightness of the threads between the suction cup sleeve and the passageway seat. The piston is composed of a needle/rod made of metal or plastic, and the other end of the piston is fixed on the piston seat. The upper surface of the piston seat is provided with a connecting rod which can transmit higher force to the piston seat.

Drawings

The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:

fig. 1 is a schematic cross-sectional view of a complete channel.

Fig. 2 is a schematic of a handheld multichannel pipette.

Detailed Description

In one embodiment, a pipette is provided which consists of a fixed channel mount, conveniently detachable movable channel heads, a movable plunger and a housing, which comprises channel units, which can transfer 48 or 96 liquid samples at a time, each liquid sample having a volume of up to 8 microliters.

One complete channel unit comprises a movable channel head, a channel seat and a piston. The movable channel head consists of a 10 microliter suction head (figure 1 suction head), a suction head sleeve (figure 1 suction head sleeve) and a rubber ring (figure 1 rubber ring). The rubber ring is a silica gel O ring with the outer diameter of 5 mm, the inner diameter of 1 mm and the thickness of 2 mm. The upper part of the suction head is provided with a flange. The suction head sleeve is of a hollow structure, the inner surface of the suction head sleeve is provided with a boss which is matched with the upper part of the 10 microliter suction head, so that the flange at the upper part of the suction head is erected in the boss at the inner surface of the suction head sleeve, the suction head cannot fall off from the suction head sleeve, and the outer surface of the upper half part of the suction head sleeve is provided with threads. The suction head is arranged in the suction head sleeve, the tip end of the suction head protrudes out of the lower opening of the suction head sleeve, and the rubber ring is arranged on the upper part of the suction head to form the movable channel head.

The center of the section of the channel seat (figure 1) is provided with an axial channel hole, the lower surface of the channel seat is provided with a cylindrical recess, and the recess is internally provided with a thread matched with the thread on the outer surface of the suction head sleeve. The channel block in figure 1 shows only one unit of the channel block, and when 12 such units are arranged in a row, and a total of 8 rows, a 96-channel block is formed.

The piston is a stainless steel column (piston in figure 1) with the diameter of 1 mm, the upper end of the piston is fixed on the piston seat, and the lower end of the piston can be inserted into the axial channel hole of the channel seat and the inner hole of the rubber ring.

The piston is inserted into the channel seat, and the external screw thread of the suction head sleeve in the movable channel head is matched and screwed with the screw thread in the recess on the lower surface of the channel seat, so that the movable channel head and the suction head are assembled into a complete channel unit.

The sealed cavity in figure 1 refers to a semi-sealed space which is only provided with a sucker tip outlet and is formed by the piston, the rubber ring and the sucker inner surface when the above parts are assembled together. When the tip of the pipette tip is immersed in a liquid and the piston is raised, the air pressure in the sealed chamber drops, drawing liquid from the pipette tip. Otherwise, the liquid is discharged from the tip of the tip.

The complete channel of figure 1 shows a section of a channel unit, which when the tip holder is screwed clockwise into the channel seat, drives the tip towards the rubber ring, creating a well-sealed contact surface between the tip and the rubber ring. The inner diameter of the extruded rubber ring can contract inwards, so that the piston can be extruded simultaneously, and the contact surface between the piston and the rubber ring can obtain good sealing performance. The sealed cavity thus formed has good sealing properties in the upper half. By adjusting the tightness of the threads, good sealing performance can be achieved, and meanwhile, the piston does not have large resistance to movement. The surface of the piston is coated with a lubricant, so that the resistance can be further reduced.

Each movable channel head can be conveniently replaced and adjusted in air tightness, so that the whole equipment is very easy to maintain, only damaged channel heads need to be replaced, and the channel seat and the piston are not easily damaged parts.

In the section of the complete channel unit of fig. 1, the width of the section is 9 mm, and when a plurality of such units are arranged side by side, the pitch of each unit is consistent with the standard pitch of a common 96-well plate, and when 96 such units are arranged in the arrangement of the 96-well plate, the parallel pipetting of 96 samples can be realized. Parallel pipetting of any number of samples up to 96 can be achieved by removing a portion of the active channel heads, e.g., by removing the active channel heads from the even rows, a parallel pipetting of 48 samples can be achieved.

The pipette further includes a piston seat. The piston seat is positioned in the shell, and the suction head extends out of an opening at the lower part of the shell. The lower surface of the piston seat is provided with a plurality of small holes for fixing the piston, and the number and the arrangement mode of the small holes are consistent with those of the channel holes on the channel seat and are aligned with each other. The upper surface of the piston seat is provided with a connecting rod. The upper end of the housing exceeds the upper plane of the housing (figure 2), and the housing and the channel seat are fastened in a certain way, wherein the fastening way comprises screw connection, adhesion and the like. Fig. 2 shows a simple hand-held multichannel pipette that drains all channels when the upper end of the connecting rod is depressed and drains all channels when the connecting rod is raised. One or more springs are arranged on the handheld multichannel pipettor, one end of each spring is fixed on the shell or the channel seat, and the other end of each spring is fixed on the piston seat, so that the piston seat can automatically reset after the connecting rod is pressed down and when pressure is released.

The tips are not disposable and therefore are required to be cleaned and reused for pipetting different samples.

When the piston seat and the channel seat are respectively connected to an automatic device, multi-channel automatic pipetting can be realized, and the maintenance of each channel is very simple.

The embodiments of the present invention are not limited to the above-described examples, and various changes and modifications in form and detail may be made by those skilled in the art without departing from the spirit and scope of the present invention, and these are considered to fall within the scope of the present invention.

Claims

1. A multichannel pipettor, characterized in that: comprises a fixed channel seat, a plurality of detachable movable channel heads, a movable push rod and a shell; the channel head is connected with the channel seat through threads; each movable channel head consists of a pipette suction head, a rubber ring and a suction head sleeve, and the threads are positioned on the outer surface of the suction head sleeve and used for fixing the rubber ring and the pipette suction head to the channel seat; the movable push rod consists of pistons, a piston seat and a connecting rod, the number of the pistons is the same as that of the movable channel heads, and the pistons penetrate through holes in the channel seats and are inserted into the rubber rings.

2. The multichannel pipette according to claim 1, wherein the fixed channel seat is a rectangular parallelepiped having a length of 10 to 15 cm, a width of 7 to 10 cm and a height of 1 to 2 cm, and has 4 or 8 rows of 8 or 12 channel holes each, each channel hole communicating with both the upper and lower surfaces of the channel seat, the channel holes being arranged at equal intervals in the same row, wherein the intervals are 4.5 mm, 9 mm or 18 mm, and the intervals between the rows are equal, and the row intervals are 4.5 mm, 9 mm or 18 mm.

3. The multichannel pipette according to claim 1 or 2, wherein the channel bore lower opening is surrounded by a ring of cylindrical recesses having threads therein, the threads matching the threads on the movable channel head.

4. The multichannel pipette according to claim 1, wherein in the moving channel head, the pipette tip is a 10, 200 or 1 microliter tip, the inner surface of the tip cap is sized to the outer surface of the tip so that the tip of the tip protrudes from the lower opening of the tip cap, the butt of the tip is in contact with the rubber ring, and the outer diameter of the rubber ring is the same as the outer diameter of the butt of the tip so that the rubber ring can lie flat on the butt plane of the tip; the upper half part of the suction head sleeve is a sleeve with an upward opening, the inner diameter of the sleeve enables the thick end of the suction head to be placed in the sleeve, and the outer surface or the inner surface of the sleeve is provided with threads for matching with the threads on the channel seat.

5. The multichannel pipette of claim 1, wherein the diameter of the piston is the same as or slightly smaller than the inner diameter of the rubber ring, such that when the bottom of the piston enters the rubber ring, the inner hole of the rubber ring is blocked, thereby forming a seal on the contact surface between the piston and the rubber ring, and simultaneously forming a seal on the contact surface between the rubber ring and the butt of the pipette tip; (ii) a The piston is composed of a needle/rod made of metal or plastic, the other end of the piston is fixed on the piston seat, and the upper surface of the piston seat is provided with a connecting rod.