Gel chromatography is also known as molecular sieve filtration and exclusion chromatography. Gel is a kind of porous material without surface charge. When the sample solution with a variety of components moves in the gel, the speed is fast or slow due to their different molecular weights. When the buffer is elution, the substance with large molecular weight cannot enter the gel hole, and the movement between the gels is almost vertical downward. The substance with small molecular weight enters the gel hole for a "bypass" operation, so that it can flow out of the gel column successively according to the size of the molecular weight to achieve the purpose of separation. Gel chromatography can be used for desalination, separation and purification, determination of molecular weight of polymer substances, concentration of polymer solution, etc. It has the advantages of simple equipment, convenient operation, rapid separation and no influence on molecular biological activity.

Step 1: Swelling

Take the required dry glue, swell with 5 times deionized water, set aside after 2 hours.

Step 2: Install the column

1. Gel chromatographic sampling, balancing and elution only use a buffer solution with low salt concentration; Optional Tris- hydrochloric acid, PBS buffer near neutral.

2. The gel is drained, the initial buffer (gel to buffer = 3:1 ratio) is prepared into a homogenate and degassing.

3. The chromatographic column is fixed vertically, the bottom end is moistened with water or buffer and the liquid level is maintained for a period of time.

4. Pour the homogenate along the inner wall of the column at one time with a glass rod to make the gel settle freely in the column, water seal the chromatographic column, and settle overnight.

5. Connect the movable cylinder at the top of the column, turn on the peristaltic pump, let the buffer flow rate flow through the volume of 5 columns when used, and then use 1.5 times the operating flow rate to flow through the volume of 5 columns, adjust the adaptive cylinder head, so that it is as close to the rubber surface as possible, and finally balance the column with 2-3 times the buffer volume.

Note: The use of gel filtration media has high requirements for column loading, and the column loading effect can be tested by acetone-aqueous solution with equal plate height. No bubbles can be introduced in all operation processes to ensure the uniformity of loading.

Step 3: Balance

The buffer is balanced at the operating flow rate to balance the chromatographic column, and the detector changes are observed until the conductivity, pH, and other parameters are unchanged.

Step 4: Sample delivery

Switch the transfer valve for sample loading, and the amount of sample loading should be reduced as much as possible; Sample pretreatment: desalting, preparation of equilibrium solution, 0.45mm microporous membrane filtration.

Step 5: Elution

Eluting with buffer, keep the flow rate constant.

Step 6: Regenerate