title: Use of dried blood for measurement of trans fatty acids.
abstract: BACKGROUND
  Fatty acid measurements especially trans fatty acid has gained interest in recent times. Among the various available biomarkers, adipose tissue is considered to be the best for the long term dietary intake but the invasive nature of tissue aspiration reduces its utility. Phlebotomy is a much less invasive method of sample collection when a large number of participants are involved in the study and therefore is an alternative, most suitable for large population based studies. In the present study fatty acid (with special emphasis on trans fatty acid) extraction from blood spotted and dried on filter paper was carried out to simplify the sample collection procedure and transportation.
  
  
  METHODS
  Blood samples were collected from 19 healthy volunteers. The blood was spotted (30 spots of 10 microl each) on filter paper, dried at room temperature and stored at 4 degrees C in zip-lock poly bags. For comparison whole blood stored at -70 degrees C was simultaneously analyzed.
  
  
  RESULTS
  A good agreement was seen between trans fatty acid values obtained in dried blood and whole blood as evident from the pearson correlation coefficients ('r' for monounsaturated (trans) 0.70 and for polyunsaturated (trans) 0.692 respectively). The intraclass correlation coefficient for monounsaturated trans was 0.805 and for polyunsarurated trans was 0.776.
  
  
  CONCLUSIONS
  Dried blood spots can be used for trans fatty acid analysis.
authors.affiliation: Department of Cardiac Biochemistry, All India Institute of Medical Sciences, Ansari Nagar, New Delhi-110029, India. g_ruby2123@yahoo.co.in
authors.forename: Ruby
authors.initials: R
authors.lastname: Gupta
authors.forename: Ransi Ann
authors.initials: RA
authors.lastname: Abraham
authors.forename: Savita
authors.initials: S
authors.lastname: Dhatwalia
authors.forename: Lakshmy
authors.initials: L
authors.lastname: Ramakrishnan
authors.forename: Dorairaj
authors.initials: D
authors.lastname: Prabhakaran
authors.forename: Kolli Srinath
authors.initials: KS
authors.lastname: Reddy
mesh_terms: D001800:Blood Specimen Collection / Q000379:methods; D005229:Fatty Acids, Monounsaturated / Q000097:blood; D005374:Filtration; D006801:Humans; D010209:Paper; D013048:Specimen Handling / Q000379:methods; D044242:Trans Fatty Acids / Q000097:blood*
chemical_list: D005229:Fatty Acids, Monounsaturated; D044242:Trans Fatty Acids