The development of new density gradient media for purifying human islets and islet-quality assessments. by Huang, G, Zhao, M, Jones, P, Persaud, S, Ramracheya, R, Löbner, K, Christie, MR, Banga, J, Peakman, M, Sirinivsan, P, Rela, M, Heaton, N, Amiel, S