ALFA Selector CE (Incl. 10 mg elution peptide)

ALFA Selector CE (for “Cold Elutable”) is an innovative affinity resin designed for the highly efficient purification of ALFA-tagged proteins at low temperatures in physiological buffers. Please look to our Technology Section for more information about the ALFA system.

ALFA Selector CE is based on a medium-affinity (Kd ≈ 100 nM) single-domain antibody (sdAb) that is covalently immobilized on 4% cross-linked agarose or magnetic agarose beads. ALFA Selector CE is optimized for an efficient, competitive elution using physiological buffers at 4 °C using ALFA elution peptide. For this purpose, every unit of ALFA Selector CE is supplied with 10 mg of ALFA elution peptide, which is sufficient for 25 mL of elution buffer. if more ALFA elution peptide is needed, they can be purchased here.

Alternatively, elution can be performed under acidic or denaturing conditions. ALFA Selector CE can be regenerated using acid or basic conditions (100 mM Glycine pH 2.2, 150 mM NaCl, or 100 mM NaOH, respectively) and does not lose capacity even after 10 regeneration cycles. The innovative, oriented and selective attachment via a flexible linker guarantees high accessibility of the sdAbs and largely eliminates batch-to-batch variations.

Due to the single-chain nature of sdAbs and their covalent attachment, no “leakage” of light and heavy chains from IgGs is observed during elution, even under harsh conditions (e.g., SDS sample buffer).

ALFA Selector CE thus features high specificity and superior capacity for ALFA fusion proteins while showing negligible non-specific background. ALFA Selector CE is compatible not only with physiological buffers but also with high stringency buffers (see ALFA Selector Manual). ALFA Selector CE thus provides great freedom to adjust the binding and washing conditions to the experimental needs.