SKU	Name	Unit	Price	Delivery
B5K007	Protein Desalting Column (5K MWCO)	25支0.7ml	$221	10days
B5K050	Protein Desalting Column (5K MWCO)	10支5ml	$150	10days
B5K080	Protein Desalting Column (5K MWCO)	10支8ml	$183	10days
B5K100	Protein Desalting Column (5K MWCO)	10支10ml	$210	10days

Description Operation References

Protein Desalting Spin Column is an advanced dextran‑based desalting device. Its working principle relies on the molecular sieve effect of the dextran gel with a network structure, which separates substances based on molecular size. The protein desalting column retains more than 95% of salts and small molecules, provides near‑volume recovery without sample dilution, and delivers excellent desalting performance while maintaining high protein recovery. This product eliminates the need for column packing and replaces time‑consuming traditional dialysis, enabling rapid protein purification or buffer exchange. With just a few simple centrifugation steps, it can desalt and exchange buffers for sample volumes ranging from 100 μL to 3 mL, ensuring trouble‑free operation.

» High Recovery – Low‑binding resin maximizes protein recovery.

» Fast – No need to wait for gravity‑driven flow; centrifugation enables rapid processing.

» Cost‑effective – More economical and practical than other commercially available prepacked columns.

» Reusable – Can be regenerated and reused.

Operation Steps

1. Equilibration of the Desalting Column

a. Remove the bottom cap of the spin column by first twisting it gently in one direction, then in the opposite direction. Place the column back into the collection tube and centrifuge at 1000 × g for 1 minute. Discard the storage solution collected in the tube.

b. Return the spin column to the collection tube, add 250 μL of equilibration buffer (the buffer intended for the desalted sample), and let it stand until the buffer is completely absorbed by the resin. Centrifuge at 1000 × g for 1 minute. Repeat this step three times, discarding the flow‑through each time.

2. Sample Processing

Place the spin column into a clean microcentrifuge tube. Add 100 μL to 200 μL of sample, let it stand for 3 minutes, and then centrifuge at 1000 × g for 1 minute. The solution in the tube is the desalted sample.

3. Regeneration and Storage of the Desalting Column

For a used desalting column, add 300 μL of 0.5 M NaOH solution, let it stand for 2 minutes, and centrifuge at 1000 × g for 1 minute. Repeat this step twice. Then add 300 μL of deionized water, let it stand for 2 minutes, and centrifuge at 1000 × g for 1 minute; repeat three times. After regeneration, add 20% ethanol solution to the column, replace the red bottom cap, and tighten the cap. Store at 2–30 °C.

Operation

Recommended Maximum Sample Loading Volume

Protein Desalting Column (Volume)	Maximum Sample Volume
0.7 mL column	200 μL
5 mL column	1.5 mL
8 mL column	2.4 mL
10 mL column	3 mL

Precautions

The sample volume should be within the column’s processing capacity. Excessive volume may lead to incomplete desalting, while insufficient volume may reduce sample recovery.
The resin may dehydrate and shrink in high‑concentration alcohol solutions or saturated salt solutions. Do not load such solutions onto the column.
When loading the sample, try to distribute it evenly over the center of the column bed.
If the sample concentration is too low, concentrate it to the desired volume or concentration before desalting.

Frequently Asked Questions

1. Low Protein Recovery

Possible Causes:

a. Protein concentration is too low (<0.01 mg/mL).

b. The buffer composition or pH used for exchange is not optimal, leading to non‑specific adsorption.

Solution:

a. Concentrate the protein solution appropriately before desalting.

b. Replace with a suitable buffer and fully equilibrate the prepacked column 2–3 times.

2. Turbidity or Precipitation After Protein Recovery

Possible Causes:

a. The buffer used is not optimal.

b. Certain ions in the buffer have been removed, causing protein aggregation near its isoelectric point.

Solution:

Replace with a suitable buffer and fully equilibrate the prepacked column 2–3 times.

3. Incomplete Desalting

Possible Cause:

The salt ion concentration is too high (>0.5 M).

Solution:

Increase the number of desalting steps appropriately based on the salt concentration, or dilute the sample before desalting.

Protein Desalting Column (5K MWCO)

Operation

References