JPH01195357A - Electrophoretic device - Google Patents

Abstract

PURPOSE:To enable migration always at a constant temp. so that data having reproducibility is obtd. even if thermal environment changes by directly detecting the temp. of the gel medium itself and controlling a high-voltage power supply in accordance with the signal corresponding to the detected temp. CONSTITUTION:The permissible range of the migration temp. is first set and the migration temp. is monitored via a thermocouple 4 by a CPU 8 which monitors both of the high-voltage power supply 7 and a cooling block 2. The voltage is raised until the upper limit of the migration temp. is attained if said temp. is in a permissible range. The specified voltage is maintained until the heat diffuses and the same temp. as the cooling temp. is attained upon attaining of the upper limit. This operation is repeated until the upper limit of the voltage impression is attained and thereafter the specified voltage is maintained. The voltage is once lowered and after the state stabilizes, the voltage is again raised up to the upper limit of the impression if the upper limit tem. is exceeded in the constant voltage state. The migration is thereby effected always in the constant temp. state and the data having the reproducibility is obtd. even if the thermal environment changes.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a nine isoelectric focusing device, particularly temperature control.

(b) A prior art isoelectric focusing device is one in which a sample is placed in a gel medium and a voltage is applied to both ends of the gel medium to cause each substance in the sample to migrate to a pH position corresponding to its isoelectric point.

The temperature of the medium influences the electrophoretic mobility of the sample, and as the temperature of the medium changes, the electrophoretic mobility of the sample also changes.

In addition, in the case of isoelectric focusing, pH is affected by temperature, so in consideration of reproducibility, it is desirable to maintain a constant temperature state during electrophoresis.

Conventionally, the gel/L' medium was equipped with a temperature control device, and the temperature of the circulating fluid flowing through the temperature control device was controlled to maintain the gel medium at a constant temperature. For example, the circulating fluid used here is 1
0″C cooling water was used.

Further, as a method other than this, there is a method of controlling the temperature by using electric power supplied during electrophoresis in addition to controlling the circulating liquid for temperature adjustment. This sets the power to a predetermined wattage and controls the voltage to reach the set wattage. Generally gay/L
/Since the resistance of the medium increases over time, the voltage is increased stepwise to keep the power constant.

(c) Problems to be Solved by the Invention In the method of controlling the temperature of the circulating fluid for temperature regulation, polyacrylamide, which is a separation medium for electrophoresis, has poor heat conduction, so the temperature of the gel during electrophoresis can be accurately controlled. I couldn't say that I was doing it.

In addition, although voltage control using electricity can control the energy applied, the actual temperature of the gel itself cannot be fully controlled. This is because the thermal environment in which the gel is placed was not considered. Therefore, for example, even if the temperature of the gel was controlled to be maintained at 10"C, there was an error of +5 to 10C.

The object of the present invention is to detect the actual temperature of the gel and perform power control based on this value.

B) Means for Solving the Problems The present invention provides an electrophoresis apparatus in which a temperature control device is attached to a gel plate for electrophoresis. The present invention is characterized in that it includes a control means that performs voltage control based on the voltage control.

Here, a thermocouple is used as the temperature detection means, and since the thermocouple directly measures Ge/l' during migration, it is necessary to
be strictly insulated.

(E) Function In the present invention, the temperature of the medium itself is detected by the temperature detection means, and it is monitored whether the temperature is within the temperature range controlled by the temperature control device.

If it deviates from the control temperature range, the deviation is canceled by voltage control.

(f) Example An embodiment of the invention is shown in FIG.

1 is a gel for electrophoresis, and 9 is housed in a case made of ceramics such as SiC or alumina.

A cooling block 2 is installed in the electrophoresis gear A/1.
Cooling water is circulated through the cooling block. cooling block 2
The temperature is adjusted with a thermomoji, -/L/3.

Thermocouple 4 detects the temperature of the gel itself, and thermocouple 4 is insulated with a thin film coating of fluororesin or ceramic. The signal from the thermocouple 4 is monitored by the CPU 8, and the CPU 8 also monitors the temperature of the cooling block 2, and controls the high voltage power supply 7 based on the migration temperature from the thermocouple 4.

In addition, 5. ．． 6 is a groove for the electrolyte, 5 contains 0.05 M aspartic acid as the electrolyte, and 6 contains 0.1 MNa.
OH is included.

A positive electrode is connected to the electrolytic solution 5, and a cathode is connected to the electrolytic solution 6.

In the above configuration, temperature control is performed as follows.

First, an allowable range of electrophoresis temperature is set, and the CPU 8 monitors the electrophoresis temperature via the thermocouple 4 to monitor both the high voltage power supply 7 and the cooling block 2.

If the running temperature is within an acceptable range, increase the voltage until the upper limit is reached. This is because, in general, the separation power is proportional to the potential gradient, and the higher the voltage, the better the separation power becomes.

When the upper limit of the allowable range is reached, the heat is diffused and the voltage is kept at a constant voltage until the temperature reaches the same as the cooling temperature (lower limit of the allowable range).

However, if the upper limit temperature is exceeded in a constant voltage state, the voltage is lowered once, and after the condition becomes stable, the voltage is raised again to the upper limit.

In addition, in the explanation so far, the thermocouple 4 is provided at only one location, but a plurality of thermocouples may be provided at equal intervals on Ge/I/1 and the average value of these thermocouples may be taken.

Alternatively, the location where the resistance of Ge/L/1 is the highest or the location where the tab temperature increases the most may be detected and installed there.

(G) Effect The present invention directly monitors the temperature of the gel and controls the voltage, so that electrophoresis can always be performed in a constant temperature state.

In addition, reproducible data can always be obtained even if the thermal environment changes.

[Brief explanation of the drawing]

FIG. 1 shows a schematic diagram of an electrophoresis apparatus according to the present invention. 1-Electrophoresis gauge/I/2-・Cooling block 4-・Thermocouple

Claims (1)

[Scope of Claims] 1. In an electrophoresis apparatus in which a temperature control device is attached to a gel plate for electrophoresis, there is provided a temperature detection means for detecting the temperature of the gel medium itself, and voltage control is performed based on a signal from the temperature detection means. An electrophoresis device characterized by comprising a control means.