Use of Gel Filtration and Polyethylene Glycol in the Preparation of Fluorochrome-Labelled Proteins

Fluorescent Protein Conjugates

“…(78 -82) In case Sephadex, used for the separation of fluorescein isothiocyanate labeled conjugates, becomes contaminated with dye which cannot be removed by simple elution, the gel can be purified by a treatment with H 2 0 2 • (83) After the isolation of the labeled protein, its dilution may be so high that at this point reconcentrating is desirable. This can be achieved by adding dry Sephadex to the solution of the conjugate, followed by filtration or centrifugation, (84) by dialysis versus a concentrated solution of a watersoluble, high molecular weight polymer, such as Carbowax, (81) or by pressure dialysis. (76) 3.3.…”

Principles and limitations of immunohistochemical methods

“…This removal, formerly quite a problem, can now easily be performed by a simple gel filtration with Sephadex G 20 or SO. (Lipp, 1961;Zwaan & Dam, 1961;Wagner, 1962). There is still another problem, however, which deserves consideration; the coupling (at least as investigated for fluorescein isothiocyanate and isocyanate; Curtain, 1958;Goldstein et al, 1961) causes an uneven loading of the protein molecules with fluorescent dyes.…”

Chromatography

“…A possible exception may be the lipoproteins (180, 586, 690), which are not so strongly adsorbed. Gel filtration methods (295,323,677,686,929,1312), on the other hand, offer some exciting possibilities for the separation of proteins according to molecular size. Schramm and Mohr (777,1042) have described an interesting purification method for neuraminidase, based on filtration through a column of kieselguhr, mixed with erythrocyte stromata.…”