JPH03167469A - Method for making polyacrylamide plate transparent - Google Patents

Abstract

PURPOSE:To preserve a polyacrylamide plate as a transparent flat plate by a method wherein a gel like plate is immersed in an org. solvent solution to remove moisture and subsequently dried and solidified before softened under heating to be molded on a metal plate. CONSTITUTION:When a gel like flat plate 1 is immersed in an org. solvent or a solution mixture of said solvent and water while holding a flat plate shape, the gel like flat plate discharges moisture to become a hard transparent plate in a gel like state. Next, this transparent plate is held between flexible saran nets to be placed on a ventilation support table 5 and dried and solidified by air of room temp. flowing in parallel to the surface of the plate or in a natural state. In order to correct the slight distortion generated at this time, the flat plate 1 is received in a soft binder 9 and immersed in hot water to be softened and subsequently held between metal plates 13, 14 to be cooled and cured.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is directed to drying and curing a gel-like polyacrylamide plate used as a molecular sieve material for electrophoresis or a sample distribution support after electrophoresis to become a transparent plastic plate. It is about the method.

Conventional technology Polyacrylamide gel is most commonly used in fields such as biology, chemistry, and medicine as a molecular sieve material for separating and analyzing biological substances and chemicals, and especially as a support for the distribution of sample components by electrophoresis. There is.

The polyacrylamide gel used as a material for two-dimensional electrophoresis is usually desirably a flat plate with a thickness of about 1 to 2 m+n and an area of about 10 squares. In this case, it is convenient to use a pre-prepared gel, as preparing such a flat gel for each analysis requires a great deal of labor and time. 1+m
There are many cases of some degree.

Problems to be Solved by the Invention Therefore, in order to obtain a plate-shaped gel having a thickness of one layer or more, it was necessary to perform a cumbersome preparation work every time electrophoresis is performed.

On the other hand, after performing electrophoresis, the plate-shaped gel is used to stain and measure the sample distributed within this plane, but conventionally, for preservation, it is stored in a vacuum chamber of a gel dryer with filter paper etc. attached to the bottom surface. It was then heated and dried under reduced pressure to harden it. However, in this drying method, the gel shrinks during drying and has a thickness of about 1 mm to prevent it from breaking due to the attached filter paper.
, 2Ifi+1. ■The gel is pasted onto a support such as filter paper and dried while being compressed.
The gel plate remains stuck to the filter paper and cannot be restored to its original shape. ■Even if the gel plate is flat when dry, it often bends when stored while being stuck to the filter paper, which is inconvenient. ■Gel dryers require not only a vacuum pump, but also a heater, temperature control circuit, and timer, making them relatively expensive.

There are drawbacks such as.

The present inventor has previously solved the above-mentioned drawbacks in the storage of polyacrylamide gel plates, and has developed a method that allows polyacrylamide gel plates to be easily dried and stored in a simple manner, and to easily restore their original shape. The company has developed a drying and preservation method and has already applied for a patent (Japanese Patent Application Laid-open No. 1-147356).

The method of the above-mentioned prior application involves immersing a gel-like polyacrylamide plate as a molecular sieve material for electrophoresis or a support for sample distribution after electrophoresis in a liquid containing an organic solvent as the main component to remove water in the gel. After elution, the polyacrylamide flat plate is taken out of the liquid and dried and cured under reduced pressure while maintaining the flat plate shape without impairing the air permeability of substantially the entire surface. However, the polyacrylamide plate dried and cured by the method of this earlier application is opaque white or translucent, and when applied after electrophoresis, the sample components distributed within the slope can be directly measured (without returning to a gel state) using a densitometer. It is unsuitable for photographic processing such as density measurement, projection observation, and printing.

The present invention maintains or further improves the applicability to relatively thick (3 mm or more) plates, efficiency, and stable storage properties of the prior invention, and then converts polyacrylamide gel plates into transparent plastic plates. The purpose of this paper is to provide a method for drying.

Means for Solving the Problems In achieving the above object, the present invention provides the following steps: a) A gel-like polyacrylamide plate is immersed in a liquid containing an organic solvent as a main component to elute water in the gel, and b) ) Remove the polyacrylamide board from the liquid, sandwich it between a pair of flexible mesh sheets that can be peeled off from the board surface, and create a mesh or grid-like ventilation system maintained at a predetermined height from the base. C) Dry and solidify the polyacrylamide plate after drying and solidifying by placing it on a support stand and supporting it.
Heat to 0 to 90°C to soften; d) Lay the heated polyacrylamide plate on one flat metal plate, spread it, and then place another flat metal plate on the binder. e) This constitutes a dry storage method for polyacrylamide plates that allows polyacrylamide plates as molecular sieve materials or sample distribution supports to be stored in the form of transparent flat plates.

Function The method of the present invention takes advantage of the fact that polyacrylamide is originally a plastic, and by immersing polyacrylamide in a solution containing a certain organic solvent to elute water in the gel, the final shrinkage size is quite close to that of the polyacrylamide gel. After shrinking while maintaining the flat plate shape to the desired size, the plate is further maintained in its flat shape without impairing the air permeability of the surface, dried at room temperature, and finally heated and softened to straighten the plate. As a result, the area shrinks to about 1/2 and the volume to about 1/3, forming a completely cured flat gel plate for preservation.

In this case, in the prior invention, the drying of the gel plate was promoted under vacuum reduced pressure, but in the present invention, the gel plate after dehydration is dried naturally or by a breeze from the side, so the colloidal particles constituting the gel It is thought that one of the reasons for maintaining transparency is that the network structure does not unnaturally deform due to the rapid evaporation of water, which is a dispersion medium.

Description of Examples In the examples, gels are prepared after electrophoresis, stained and bleached, or simply gelled, with a concentration of 1.
8% (mo/acrylamide: bisacrylamide = 18
0:5) and was made into plastic according to the following procedure.

(i) Immersion of raw gel in solution In FIG. 1, the gel-like polyacrylamide plate (1) as a material for two-dimensional electrophoresis or as a sample distribution support after electrophoresis is made of an organic solvent, preferably ethanol, or A solution consisting of a mixture of this organic solvent and water (2
) is immersed in a vat (3) containing a in this case,
The polyacrylamide flat plate (1) is supported on a Saran net (4) placed at the bottom of the vat (3) so that the entire surface of the polyacrylamide plate (1) is in contact with the solution (2) almost evenly while maintaining its flat plate shape. In this state, the polyacrylamide gel releases its moisture into the mixed solution and shrinks while accepting some organic solvent, forming a relatively hard transparent plate that maintains its gel state.

(n) Drying After the transparent polyacrylamide flat plate (hereinafter sometimes abbreviated as "gel flat plate") formed as described above is removed from the vat (3), peeling is applied to both sides of the flat plate (1). A possible pair of flexible mesh sheets, in this case also saran mesh (4°), are stacked one on top of the other, and this sandwich is supported by lying on a breathable support (5) as shown in Figure 2. . This breathable support stand (5) maintains a mesh or grid-like breathable upper surface (6) at a predetermined height from the laboratory table and other base surfaces (7), and also extends the lower surface of the polyacrylamide flat plate (1). This is a support structure for maintaining the same ventilation condition as the upper surface, and for convenience, a test tube stand or the like can be used. In order to accelerate the drying of the gel plate, a fan or other air blowing means is used, but this is a room temperature air blowing means that does not use a heater. The wind shall be sent parallel to the board surface. This wind speed may correspond to the so-called "breeze" or "low wind" mode of an electric fan, in which case the drying process is completed in a few hours.

On the other hand, in natural drying without air blowing as described above, if the thickness of the gel plate (1) is about 1 ++ ui, it will dry for about 24 hours, if it is about 2 inches, it will dry for about 2 days, and for about 3 layers. If so, it will take about 3 days.

(iii) Straightforward In the above drying step, the gel plate (1) dries and solidifies in a substantially flat shape, but it is usually unavoidable that some distortion occurs. Therefore, in order to straighten this as a straight plate (straighten), appropriate heating straightening is performed. That is, in FIG. 3, the gel flat plate (1) is housed in a flat bag-shaped soft binder (9), and after substantially eliminating the air in the binder, the opening fastener (10) is removed.
conclude. This binder (9) is attached to a suitable bat (11).
) filled within the range of 10 to 90°C, preferably about 70 to 8
The gel plate (1) is vertically immersed in hot water (12) at 0°C.
completely submerged in the hot water (Step 2). When left in this state for one to several minutes, the gel plate (1) is heated by the temperature of the water and becomes soft. Note that if the water temperature exceeds 90° C., there is a risk that the solvent or water in the gel will boil or rapidly evaporate, deforming the gel structure.

Now, lift the soft binder (10) out of the hot water (12) and place it on a flat metal plate (l3) as shown in Figure 4, and insert the gel flat plate (1) from the outside of the binder (9). The distortion is corrected by manual operation to make it into a flat shape, and another metal plate (14) for weight is placed on top of this and left for one to several minutes. (Note that if the gel plate is heated in air rather than in hot water, a soft binder is not necessary, and the gel plate after heating can be sandwiched between metal pieces as is.) In this way, the gel plate ( 1) is a metal plate (13),
(14), heat is removed and the material is cured while being kept flat.

By carrying out the above steps, a transparent plastic flat plate of polyacrylamide is obtained, which can be taken out from the soft binder (9) and sealed in a packaging means such as a plastic bag for long-term storage. In this case, it can be stored stably for a long period of time, especially if it is placed between cardboard booklets such as photo albums at room temperature.

Things to be careful of when carrying out each of the above steps are:
■ Do not moisten the gel plate after the drying process.
■During drying, there may be a difference in ventilation between the top and bottom surfaces of the gel plate, or other malfunctions, such as those shown in Figure 5.
Even if significant curvature occurs due to drying on the base surface (7), do not attempt to flatten it by applying external force such as pressing with your hands. In other words, at this stage, the gel plate has considerable hardness, so there is a risk of it breaking. (Sufficient correction is possible in the next straightening process.) In the case of decolored gel, the decolorizing solution used immediately before is 40 to 45
% methanol or ethanol, it may be considered equivalent to the solution immersion in the first step and may be directly entered into the second step drying process after being pulled out of the decolorizing solution. However, in that case, a small amount of acetic acid contained in the decolorizing solution remains in the gel, so if you want to be exact, it is better to perform the first step (immersion treatment in ethanol solution) after decolorizing. Good.

Effects of the Invention As mentioned above, the polyacrylamide flat plate thus obtained can be stored for a long period of time at room temperature without using any special desiccant if it is sealed in a plastic bag. If distortion occurs during storage, the above-mentioned straightening process can be repeated.

When the plasticized polyacrylamide plate is immersed in water or 40-45% ethanol, it returns to a gel state.

Gelu plus like this Tic transfer is reversible and occurs many times.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of the container showing the process of soaking the gel plate in the solution, Figure 2 is a cross-sectional view of the drying process, Figure 3 is a front view with both sides broken away showing the first stage of the straight process, and Figure 4 is the straight-sided process. FIG. 5 is a cross-sectional view showing the second step of the process, and is a partial cross-sectional view when an undesired curve occurs in the gel plate drying process. (1)・・・・・・・・・・・・・・・Polyacrylamide flat plate (2)・・・・・・・・・・・・・・・
... Soaking solution (3), (11) ... ... Bat (4), (4') ... Saran net (5
)・・・・・・・・・・・・・・・・・・Breathable support base (6)・・・・・・・・・・・・・・・・・・Breathable top surface (7)・・・・・・・・・・・・・・・・・・Base surface (8)・・・・・・・・・・・・・・・Wind direction arrow (9)・・・・・・・・・・・・・・・・・・Soft binder (10)・・・・・・・・・・・・・・・・・・
Opening fastener (12)・・・・・・・・・・・・・・・
...Metallic plate patent applicant Akira Wada Figure 3 Figure 4 Figure 5

Claims (2)

[Claims] (1) a) A gel-like polyacrylamide plate is immersed in a liquid containing an organic solvent as a main component to elute the water in the gel, and b) The polyacrylamide plate is taken out from the liquid and the plate surface is It is dried and solidified by being sandwiched between a pair of flexible mesh sheets that can be peeled off from the base and supported by lying on a mesh or lattice-shaped breathable support stand maintained at a predetermined height from the base. c) The polyacrylamide plate after drying and solidification is
heating to 0 to 90°C to soften; d) After heating, the polyacrylamide plate is laid down on one metal flat plate, spread, and then another metal flat plate is placed on top of it. e) A dry storage method for a polyacrylamide plate, which is characterized in that it enables the polyacrylamide plate used as a molecular sieve material or a sample distribution support to be stored in a transparent flat plate form. (2) In the step of supporting the polyacrylamide plate sandwiched between the pair of peelable flexible net sheets by laying it on a net-like or lattice-like support base, and drying and solidifying the polyacrylamide plate, the polyacrylamide plate is placed directly beside the polyacrylamide plate. 2. A method according to claim 1, characterized in that the drying process is accelerated by blowing air parallel to the surface.