title: β-actin as a loading control for plasma-based Western blot analysis of major depressive disorder patients.
abstract: Western blot analysis is a commonly used technique for determining specific protein levels in clinical samples. For normalization of protein levels in Western blot, a suitable loading control is required. On account of its relatively high and constant expression, β-actin has been widely employed in Western blot of cell cultures and tissue extracts. However, β-actin's presence in human plasma and this protein's putative role as a plasma-based loading control for Western blot analysis remain unknown. In this study, an enzyme-linked immunosorbent assay was used to determine the concentration of β-actin in human plasma, which is 6.29±0.54 ng/ml. In addition, the linearity of β-actin immunostaining and loaded protein amount was evaluated by Western blot, and a fine linearity (R²=0.974±0.012) was observed. Furthermore, the expression of plasma β-actin in major depressive disorder subjects and healthy controls was compared. The data revealed no statistically significant difference between these two groups. Moreover, the total coefficient of variation for β-actin expression in the two groups was 9.2±1.2%. These findings demonstrate that β-actin is present in human plasma and may possibly be used as a suitable loading control for plasma-based Western blot analysis in major depressive disorder.
authors.affiliation: Chongqing Key Laboratory of Neurobiology, Chongqing 400016, China; Institute of Neuroscience, Chongqing Medical University, Chongqing 400016, China.
authors.forename: Rufang
authors.initials: R
authors.lastname: Zhang
authors.forename: Deyu
authors.initials: D
authors.lastname: Yang
authors.forename: Chanjuan
authors.initials: C
authors.lastname: Zhou
authors.forename: Ke
authors.initials: K
authors.lastname: Cheng
authors.forename: Zhao
authors.initials: Z
authors.lastname: Liu
authors.forename: Liang
authors.initials: L
authors.lastname: Chen
authors.forename: Liang
authors.initials: L
authors.lastname: Fang
authors.forename: Peng
authors.initials: P
authors.lastname: Xie
mesh_terms: D000199:Actins / Q000097:blood*; D000328:Adult; D001798:Blood Proteins / Q000032:analysis*; D015153:Blotting, Western; D002138:Calibration; D016022:Case-Control Studies; D003865:Major Depressive Disorder / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D012680:Sensitivity and Specificity
chemical_list: D000199:Actins; D001798:Blood Proteins