JPH07132236A - Constant temperature device - Google Patents

Abstract

PURPOSE:To provide a constant temp. device in which plural samples are rapidly in temp. to the same temp. by making, in a heat transfer medium, plural holes in which plural sample vessels are to be individually put and other plural holes and inserting ceramic heaters into the other holes. CONSTITUTION:A constant temp. device 1 is formed of, for example, an aluminum heat transfer medium 2 in the shape of a rectangular rarablelopiped block and ceramic heaters 3. In the heat transfer medium 2, plural holes 21 in which test tubes are to be individually put and other plural holes 22 are made. Ceramic heaters 3 are inserted into the holes 22 and fixed. The holes 21 for test tubes are opened on the upper surface side of the heat transfer medium 2 and sink vertically downward. The holes 22 in which the heaters 3 are inserted are opened on the back surface of the heat transfer body 2 and provided in parallel and opposite to the holes 21. Therefore, when the distance between the test tubes put in the holes 21 and the ceramic heaters 3 fixed in the holes 22 is made constant, the densest packing arrangement in the plane direction is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermostatic device.
This thermostat is preferably used in the field of biotechnology such as gene manipulation.

[0002]

2. Description of the Related Art In biotechnology fields such as molecular biology and genetic engineering, D
There are steps such as the NA synthesis step and the heat denaturation step of DNA in which the sample in the test tube must be kept at a constant temperature for a predetermined time. This is because if the temperature is not strictly controlled, another DNA fragment will be amplified in addition to the target DNA fragment.

Conventionally, as a thermostatic device used in such a biotechnology field, a rectangular parallelepiped block-shaped heat transfer medium made of aluminum having a plurality of holes for inserting test tubes and a plate installed on the bottom surface of the heat transfer medium. A combination with a die heater is known.

[0004]

However, when the sample is heated by the conventional thermostatic device, the heat generated from the heater is dissipated from the side surface of the heat transfer medium, which makes it difficult to raise the temperature rapidly. It was Further, since there is a temperature gradient between the center and the periphery of the heat transfer medium, even if they are heated at the same time, there is a difference in temperature between the test tubes. Therefore, it was not possible to strictly maintain the sample in each test tube at the same predetermined temperature. An object of the present invention is to solve such a conventional problem and to provide a thermostatic device capable of rapidly raising and lowering the temperature of a plurality of samples to the same temperature.

[0005]

[Means for Solving the Problems] In order to achieve the purpose,
The thermostat of the present invention comprises a block-shaped heat transfer medium and a ceramic heater, and the heat transfer medium is provided with a plurality of holes for individually inserting a plurality of sample containers and a plurality of other holes, and A ceramic heater shall be inserted.

The heat transfer medium is aluminum Al.
Alternatively, an aluminum-Al alloy is desirable because it is easy to process, inexpensive, and lightweight, but the invention is not limited to this. The ceramic heater preferably has a columnar structure in which a tungsten W coil is embedded in a silicon nitride sintered body in terms of insulation and thermal shock resistance during rapid temperature rise. However, other ceramics such as aluminum nitride and alumina may be used, and the heating resistor is not limited to tungsten.
It may be a W-Re alloy or Mo, and may have a plate shape instead of the coil shape. The sample container is usually a test tube, and the holes for inserting the sample container and the holes for inserting the ceramic heater are preferably arranged in parallel and alternately.

[0007]

A heater serving as a heat source can be arranged near the sample to heat the heat transfer medium from the inside. Therefore, since the heat loss due to heat dissipation is small, the temperature can be raised rapidly, and the temperature control becomes easy. In addition, the heat capacity of the heat transfer medium is reduced by the volume of the hole for inserting the ceramic heater. Therefore, the temperature can be rapidly lowered.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A thermostatic device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 (A) is a perspective view of the thermostatic device of the present invention,
FIG. 1 (B) is a plan view of the same, and FIG. 1 (C) is a longitudinal sectional view thereof.
The thermostatic device 1 comprises a rectangular parallelepiped block-shaped aluminum heat transfer medium 2 having a size of 60 × 60 × 30 [mm] and a diameter of 3.
It consists of 12 5 mm ceramic heaters 3, 3 ... The heat transfer medium 2 has six test tubes (not shown).
.. and the other 12 holes 22, 22..22 are provided. Then, the ceramic heaters 3, 3 ... 3 are inserted and fixed in the holes 22, 22 ,.

The test tube hole 21 is open on the upper surface side of the heat transfer medium 2 and is recessed vertically downward.
The hole 22 for inserting the heater is opened on the lower surface side of the heat transfer medium 2, and is provided parallel to and opposite to the hole 21. Moreover, halls 21, 21 ... 21 and hall 2
2, 22 ... 22 are the lines parallel to one side of the cross section of the heat transfer medium 2 on the X-axis, and the line orthogonal to the line in the cross section is Y.
If the position of the axis, the hole 22 in the lower left corner of FIG. 1 (B), is [0,0], the holes 22, 22, ...
At the position of the [m, n] point (m and n are 0 or natural numbers) of the Y coordinate, the holes 21, 21 ... 21 have [(2m + 1)
/ 2, (2n + 1) / 2] points are arranged. Therefore, when the distance between the test tube placed in the hole 21 and the ceramic heater 3 fixed in the hole 22 is constant, the test tube is in the closest packing arrangement in the plane direction.

The thermostat 1 was manufactured as follows. First, the heat transfer medium 2 was obtained by machining an aluminum ingot into a rectangular parallelepiped shape and drilling each hole with a drill. On the other hand, the ceramic heater 3
Was manufactured by embedding a tungsten coil, which is a heating wire, in a base material prepared by adding a sintering aid to silicon nitride powder, and hot pressing. Then, the ceramic heater 3 was inserted into a predetermined hole of the heat transfer medium 2 and fixed with ceramic cement. Thus, the thermostat 1 was completed.

6 test tubes containing the sample are put into the holes, the ceramic heaters 3, 3 ... 3 of the thermostatic device 1 are connected in series, and a constant voltage of 20 V is applied to them, and the heat transfer medium 2 The block upper surface temperature was measured by a surface thermometer.
For comparison, a heat transfer medium having holes only on the upper surface side was placed on a plate type heater of 100 watts instead of the ceramic heater 3 and the temperature was measured in the same manner. The measurement results are shown in FIG.

As shown in FIG. 2, in the case of the thermostatic device 1, the temperature of the upper surface of the medium reaches 90 ° C. in about 2 minutes, and then 90 degrees.
C was kept (curve a). Then, when the power was turned off, the temperature rapidly dropped, and the temperature returned to room temperature in 15 minutes (curve b). On the other hand, in the case of the comparative device, it took 25 minutes to reach 90 ° C. (curve c) and to return to room temperature (curve d). Further, the temperature difference between the two samples in the center and the four samples on both sides was 0.3 ° C in the case of the thermostatic device 1, whereas it was 0.5 ° C in the case of the comparative device. there were.

[0013]

EFFECTS OF THE INVENTION It is possible to rapidly raise and lower the temperature of a plurality of samples. Therefore, if it is used for a reaction requiring strict temperature control, the reaction efficiency is improved.

[Brief description of drawings]

FIG. 1 shows a thermostatic device according to an embodiment, (A) is a perspective view thereof, (B) is a plan view thereof, and (C) is a longitudinal sectional view thereof.

FIG. 2 is a graph showing the relationship between block surface temperature and time when the temperature is raised and lowered using a thermostat.

[Explanation of symbols]

1 ... Constant temperature device 2 ... Heat transfer medium 3 ... Ceramic heater 21, 22 ... Hall

Claims (1)

[Claims] 1. A mass heat transfer medium and a ceramic heater, wherein the heat transfer medium is provided with a plurality of holes into which a plurality of sample containers are individually inserted and a plurality of other holes, and the ceramic heater is provided in the other hole. A constant temperature device that is inserted.