What is the loading capacity for purifying His tagged protein using domestically produced Ni NTA fillers?

Domestic resins often show some fine particle suspension after transport. Before packing the column, allow the resin to settle naturally, decant the upper turbid liquid, and wash several times. When packing the column, add a frit of appropriate pore size below, and install a 0.45 μm inline filter before the column to significantly reduce column clogging. For purchase quotations and lead times, it is recommended to ask the manufacturer's sales directly. Regular 1 L-scale products often are in stock or ship within one week, but high-flow or pre-activated columns may have slightly longer lead times. For the first purchase, do not buy 1 L directly; first validate performance and batch with a small package, then place a full-liter order, and request that inventory from the same batch be reserved.

For the 45 kDa His tagged protein, the domestic Ni NTA labeled loading is mostly 20-50 mg/mL for dynamic binding, but the actual value must be measured using a breakthrough curve by oneself. Take a small amount of packing material into a small column, load purified protein, collect flow through sections, use UV280 or Bradford to determine the point of saturation, and then reverse calculate the loading capacity. Measure the target protein content in the clarified lysate using a wet weight scale of 200 g bacterial cells, and then calculate the column volume based on a conservative loading of 60%. This makes it less likely to overfill and waste fillers.

Whether the binding capacity decreases after 5 regeneration cycles depends on the pretreatment. If the bacterial lysate contains a large amount of pigments, nucleic acids, or high concentrations of imidazole/EDTA, the lifespan will be shortened. It is recommended to wash each time with 0.5 M NaOH or appropriate mild conditions, then strip Ni²⁺ with EDTA and reload Ni, avoiding directly reusing the same column repeatedly without proper regeneration. When performing small-scale tests, keep a dedicated control column and compare the flow-through and elution band intensities every 3 runs using the same batch of lysate. Generally, a 10-30% decrease in binding efficiency within 5 regeneration cycles is acceptable, but the actual performance must be empirically determined and cannot be based solely on the manufacturer's claim of 5-10 reuses.

The Ni NTA agarose fillers from Tian Di Ren and Boglon can be used for routine protein purification, and have a good reputation in Tian Di Ren and small and medium-sized trials. There have been many feedbacks on Boglon amplification and industrial applications. When selecting, ask the salesperson for COA, look at the average particle size, particle size distribution, Ni ² ⁺ detachment rate, and flow rate pressure curve. It is best to apply for a trial package of about 50 mL, use your 45 kDa protein to make a small column, record the sample flow rate, elution peak, and loading capacity. The hardness of the filler and the pressure resistance of the base ball have a significant impact on the scale of 200 g bacterial cells, so don't just look at the price and loading capacity labels.