TY - JOUR
T1 - Methodology for isolation, identification and characterization of microvesicles in peripheral blood
AU - Jayachandran, Muthuvel
AU - Miller, Virginia M.
AU - Heit, John A.
AU - Owen, Whyte G.
N1 - Funding Information:
This work was supported by Novel Methodology Award from the Mayo Foundation for Medical Education and Research, CTSA grant UL1 RR024150 from the National Center for Research Resources (NCRR), a grant from the Aurora Foundation to the Kronos Longevity Research Institute; NHLBI grants HL78638, HL83141 and HL83797 and HL090639; and the American Heart Association-Scientist Development Grant AHA30503Z.
PY - 2012/1/31
Y1 - 2012/1/31
N2 - Rationale: Analyses of circulating cell membrane-derived microvesicles (MV) have come under scrutiny as potential diagnostic and prognostic biomarkers of disease. However, methods to isolate, label and quantify MV have been neither systematized nor validated. Objective: To determine how pre-analytical, analytical and post-analytical factors affect plasma MV counts, markers for cell of origin and expression of procoagulant surface phosphatidylserine. Methods and results: Peripheral venous blood samples were collected from healthy volunteers and patients with cardiovascular disease and/or diabetes. Effects of blood sample collection, anticoagulant and sample processing to platelet free plasma (PFP), and MV isolation, staining and storage (freeze-thaw) and cytometer design were evaluated with replicate samples from these populations. The key finding is that use of citrate or EDTA anticoagulants decreases or eliminates microvesicles from plasma by inducing adhesion of the microvesicles to platelets or other formed elements. Protease inhibitor anticoagulants, including heparin, preserve MV counts. A centrifugation protocol was developed in which recovery of isolated MV was high with resolution down to the equivalent light scatter of 0.2 μm latex beads. Each procedure was systematically evaluated for its impact on the MV counts and characteristics. Conclusion: This study provides a systematic methodology for MV isolation, identification and quantification, essential for development of MV as diagnostic and prognostic biomarkers of disease.
AB - Rationale: Analyses of circulating cell membrane-derived microvesicles (MV) have come under scrutiny as potential diagnostic and prognostic biomarkers of disease. However, methods to isolate, label and quantify MV have been neither systematized nor validated. Objective: To determine how pre-analytical, analytical and post-analytical factors affect plasma MV counts, markers for cell of origin and expression of procoagulant surface phosphatidylserine. Methods and results: Peripheral venous blood samples were collected from healthy volunteers and patients with cardiovascular disease and/or diabetes. Effects of blood sample collection, anticoagulant and sample processing to platelet free plasma (PFP), and MV isolation, staining and storage (freeze-thaw) and cytometer design were evaluated with replicate samples from these populations. The key finding is that use of citrate or EDTA anticoagulants decreases or eliminates microvesicles from plasma by inducing adhesion of the microvesicles to platelets or other formed elements. Protease inhibitor anticoagulants, including heparin, preserve MV counts. A centrifugation protocol was developed in which recovery of isolated MV was high with resolution down to the equivalent light scatter of 0.2 μm latex beads. Each procedure was systematically evaluated for its impact on the MV counts and characteristics. Conclusion: This study provides a systematic methodology for MV isolation, identification and quantification, essential for development of MV as diagnostic and prognostic biomarkers of disease.
KW - Anticoagulants
KW - Flow cytometry
KW - Microparticle
KW - Phosphatidylserine
KW - Pre-analytical and analytical variables
UR - http://www.scopus.com/inward/record.url?scp=84855354256&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84855354256&partnerID=8YFLogxK
U2 - 10.1016/j.jim.2011.10.012
DO - 10.1016/j.jim.2011.10.012
M3 - Article
C2 - 22075275
AN - SCOPUS:84855354256
SN - 0022-1759
VL - 375
SP - 207
EP - 214
JO - Journal of Immunological Methods
JF - Journal of Immunological Methods
IS - 1-2
ER -