title: Use of the TLX ultracentrifuge for the isolation of different density lipoproteins and effects of freeze/thawing of human plasma before ultracentrifugation.
abstract: BACKGROUND
  Isolation of different density lipoproteins by ultracentrifugation can require lengthy centrifugation times and freeze/thawing of plasma may influence recovery.
  
  
  METHODS
  We isolated a range of lipoproteins using a preparative ultracentrifuge and the TLX micro-ultracentrifuge and determined the effect of freeze/thawing of plasma beforehand.
  
  
  RESULTS
  In fresh plasma, there was no significant difference in results for small-dense low-density lipoprotein apolipoprotein B (LDL apoB) (density >1.044 g/mL) or cholesterol at density >1.006 g/mL. Freeze/thawing had no effect on closely correlated results for small-dense LDL apoB (r=0.85; p<0.0001) or high-density lipoprotein (r=0.93; p<0.0001).
  
  
  CONCLUSIONS
  The TLX micro-ultracentrifuge is a reliable alternative to the preparative ultracentrifuge and freeze/thawing has only a small effect on small-dense LDL apoB or high-density lipoprotein cholesterol.
authors.affiliation: Cardiovascular Research Group, School of Clinical and Laboratory Sciences, Core Technology Facility, University of Manchester, Manchester, UK. valentine.menys@manchester.ac.uk
authors.forename: Valentine
authors.initials: V
authors.lastname: Charlton-Menys
authors.forename: Jelena
authors.initials: J
authors.lastname: Chobotova
authors.forename: Paul N
authors.initials: PN
authors.lastname: Durrington
mesh_terms: D001800:Blood Specimen Collection / Q000379:methods*; D005615:Freezing; D006801:Humans; D008074:Lipoproteins / Q000097:blood / Q000737:chemistry* / Q000302:isolation & purification*; D010949:Plasma / Q000737:chemistry*; D013997:Time Factors; D014461:Ultracentrifugation / Q000379:methods*
chemical_list: D008074:Lipoproteins