Abstract: Objective To develop an albumin aptamer that may potentially serve as a selective ligand for albumin removal from experimental samples. Methods A single-stranded 59nt DNA library that contains 21 random oligonucleotides was synthesized in vitro．An albumin aptamer A6 was developed by SELEX technique using bovine serum albumin (BSA) as target．The enrichment of aptamer and evaluation of its binding properties were monitored by flow cytometry. The secondary structure of A6 was predicted by MFord software. Results The aptamer A6 bound to BSA strongly with a Kd of 77.4 nmol/L, and had minimal cross reactivity with control proteins including ovalbumin, IgG, and trypsin. Conclusions Aptamer A6 may have potential in albumin removal applications.

Key words: Aptamer, SELEX, BSA