Gel Electrophoresis Method to Measure the Concentration of Single-Walled Carbon Nanotubes Extracted from Biological Tissue

Abstract

A rapid and sensitive method to detect single-walled carbon nanotubes (SWNTs) in biological samples is presented. The method uses polyacrylamide gel electrophoresis (PAGE) followed by quantification of SWNT bands. SWNTs dispersed in bovine serum albumin (BSA) were used to develop the method. When BSA-SWNT dispersions were subjected to sodium dodecyl sulfate (SDS)-PAGE, BSA passed through the stacking gel, entered the resolving gel, and migrated toward the anode as expected. The SWNTs, however, accumulated in a sharp band at the interface between the loading well and the stacking gel. The intensities from digitized images of these bands were proportional to the amount of SWNTs loaded onto the gel with a detection limit of 5 ng of SWNTs. To test the method, normal rat kidney (NRK) cells in culture were allowed to take up SWNTs upon exposure to medium containing various concentrations of BSA-SWNTs for different times and temperatures. The SDS-PAGE analyses of cell lysate samples suggest that BSA-SWNTs enter NRK cells by fluid-phase endocytosis at a rate of 30 fg/day/cell upon exposure to medium containing 98 microg/mL SWNTs.

The impact of subcellular location on the near infrared-mediated thermal ablation of cells by targeted carbon nanotubes

“…This linear calibration curve was then used to estimate the unknown amount of SWNTs in the cell lysates and expressed as SWNTs/known amount of cellular protein. From the amount of SWNTs in a lysate sample containing a known amount of protein and the amount of protein/cell for NRK cells [20], the amount of SWNTs per cell was then determined. A detailed example of the calculation is presented in the Supplemental Information section (Figure S2).…”

Characterization of carbon nanotubes and analytical methods for their determination in environmental and biological samples: A review

“…A rapid and sensitive gel electrophoresis method to measure the concentration of SWCNTs in extracts obtained from biological tissues has been developed [165]. The method employs polyacrylamide gel electrophoresis (PAGE) in the presence of SDS to quantify small amounts of nanotubes.…”

Toxicity assessment and bioaccumulation in zebrafish embryos exposed to carbon nanotubes suspended in Pluronic® F-108

“…To measure CNTs in zebrafish embryo lysates, a modified SDS-PAGE protocol was used, developed previously for quantifying SWNTs extracted from cell lysates (Wang et al, 2009). Briefly, a 4% stacking gel on top of a 10% resolving gel was prepared using a Hoefer Mini Vertical Gel Caster for 10×8 cm plates with 1.5-mm thick spacers and 10-well combs.…”

“…In a previous work, we developed a simple method for extracting and quantifying CNTs from cultured mammalian cells based on the migration of CNTs in sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) (Pantano et al, 2012; Wang et al, 2009, 2011). The method has been adapted here to measure CNT uptake by zebrafish embryos.…”