[Comparison of three methods for quantitative analysis of LPO in different biological samples].
OBJECTIVE
To explore the optimized methods for detecting lipid peroxide (LPO) in biological samples and the reference value of LPO in human plasma.


METHODS
Three most commonly adopted methods were used for detecting LPO in different biological samples simultaneously, and then their linearity, accuracy, precision, stability and detecting efficiency were compared. The methods were FOX assay, Modified iodometric assay and TBARS assay. The standard curve (linearity evaluation), rate of sample recovery (accuracy evaluation), reproducibility (precision evaluation), stability of reading number (stability evaluation), as well as the detected values of LPO in different sample systems by three methods simultaneously (detecting efficiency) were evaluated. The sample systems were: isolated low-density lipoprotein (LDL), supernatant of cell culture, and human plasma.


RESULTS
When applied to detecting LPO in the isolated LDL sample system, FOX assay was found to have the most sensitive detecting efficiency, good accuracy and precision. When applied to detecting LPO in the supernatant of cell culture and human plasma sample systems, the Modified iodometric assay and TBARS assay showed better function than FOX assay; the rate of sample recovery of FOX assay 61.92% +/- 2.92% was obviously lower as compared with 99.00% +/- 2.65% of modified iodometric assay and 101.63% +/- 12.00% of TBARS assay; and the reproducibility of FOX assay 19.15% was also lower as compared with 4.36% of Modified iodometric assay and 3.14% of TBARS assay. The three methods all showed fine linearity and stability. The values of LPO concentration in normal human plasma were (14.189 +/- 4.889) mumol/L by Modified iodometric assay and (0.936 +/- 0.462) mumol/L by TBARS assay; these values were close to those in other reports.


CONCLUSIONS
FOX assay was found to be most sensitive in the three methods for measurement of LPO in a relative pure sample system (such as isolated LDL). In complex sample system, however, the Modified iodometric assay and TBARS assay showed better function. The authors suggest that suitable method be chosen according to the nature of sample, that more than one method be chosen for plasma LPO assay in the same planned analysis, and that Modified iodometric assay and TBARS assay be worth the first choice.
Deng
Feng-mel
FM
Department of Pathophysiology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu 610041, China.
Wang
Shu-ren
SR
Jing
Dong-ying
DY
Wang
Yu-fang
YF
Yang
Zhi-mei
ZM
Huang
Ying
Y
Yang
Yan-biao
YB
Wang
Xiao-ming
XM
D019963:Clinical Chemistry Tests / Q000379:methods; D005296:Ferrous Compounds / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry; D006801:Humans; D008054:Lipid Peroxides / Q000032:analysis* / Q000097:blood; D010636:Phenols; D013454:Sulfoxides; D017392:Thiobarbituric Acid Reactive Substances / Q000737:chemistry; D014992:Xylenes / Q000737:chemistry
D005296:Ferrous Compounds; D005456:Fluorescent Dyes; D008054:Lipid Peroxides; D010636:Phenols; D013454:Sulfoxides; D017392:Thiobarbituric Acid Reactive Substances; D014992:Xylenes; C016833:xylenol orange