Detection of phosphatidylserine surface exposure on human erythrocytes using annexin V-ferrofluid.
The asymmetric transbilayer distribution of phospholipids in the plasma membrane and the regulation of phosphatidylserine (PS) exposure at the cell surface of animal cells are of high physiological significance. It has been shown previously that annexin V is one of the most sensitive tools with which the presence of small amounts of PS on the outer surface of eukaryotic cells can be detected. We present here the covalent coupling of annexin V molecules to magnetic nanoparticles of maghemite. The resulting annexin V-ferrofluid is used in the magnetic separation of PS exposing cells, as illustrated for human erythrocytes modified in their phospholipid transbilayer asymmetry by the use of a calcium ionophore. Results on stored human erythrocytes and comparison with results obtained using iodinated and fluorescein-labeled annexin V are also presented.
Geldwerth
D
D
IBPC, 13 rue Pierre et Marie Curie, Paris, 75005, France. geldwerth@ibpc.fr
Helley
D
D
de Jong
K
K
Sabolovic'
D
D
Sestier
C
C
Roger
J
J
Pons
J N
JN
Freyssinet
J M
JM
Devaux
P F
PF
Kuypers
F A
FA
D017304:Annexin A5 / Q000031:analogs & derivatives* / Q000378:metabolism; D002469:Cell Separation; D004910:Erythrocyte Membrane / Q000378:metabolism*; D006801:Humans; D008051:Lipid Bilayers; D008081:Liposomes; D008280:Magnetics; D008563:Membrane Lipids / Q000097:blood*; D010718:Phosphatidylserines / Q000097:blood*; D013048:Specimen Handling
D017304:Annexin A5; D008051:Lipid Bilayers; D008081:Liposomes; D008563:Membrane Lipids; D010718:Phosphatidylserines