Uv spectrophotometer

To measure the amount of tamoxifen in LPPC, LPPC/TAMs were destroyed by chloroform and added the distilled water (DDW) for partition. The concentration of TAM remaining in the chloroform layer was then measured using a UV spectrophotometer (Amersham Biosciences, Uppsala, Sweden) at 300 nm.

The possibility of human contamination of the samples was high. So we cleaned the samples first with ethanol and 10× phosphate-buffered saline (PBS) two times. Interestingly, after two samples (AM 1 and DDN 2) were washed, what appeared to be plastic materials were noted. These samples were burnt to confirm that they were plastics, and both samples melted. Therefore these two samples were not used in the present study, whereas the other six samples were used. The outer surface (0.5 mm) of the six samples was removed using a surgical blade to remove surface contaminants, and the surface was washed again with 10 × PBS. A small section of the basal part of these samples was cut, chopped and transferred to a 2µl Eppendorf tube (Axygen, Union City, California). DNA extraction was attempted using a QIAGEN DNeasy Tissue Kit (QIAGEN, Hilden, Germany) according to the manufacturer’s instructions. To determine the quality and concentration of the DNA obtained, the samples were subjected to gel electrophoresis on a 0.8% agarose gel in 1 × TAE buffer and DNA quantified with a UV spectrophotometer (Amersham Pharmacia, Centennial Avenue, Piscataway, New Jersey, USA). All measures were taken to avoid and monitor the contamination.A negative control was included during the extraction of DNA.

The amounts of DNA released from the E. coli cells treated with N4 were measured by optical density at 260 nm (OD₂₆₀) and OD₂₈₀ using a UV spectrophotometer (Amersham Pharmacia Biotech) as described in detail in the supplemental material.