Journal: The Journal of steroid biochemistry and molecular biology

Article Title: Structure-dependent retention of steroid hormones by common laboratory materials

doi: 10.1016/j.jsbmb.2019.105572

Figure Lengend Snippet: (A) List of nine steroids used in these experiments along with experimentally determined log octanol-water partition coefficients (log Kows) obtained from Leszczynski and Schafer [9]. (B) Fraction of steroid retained after one hour incubation in D-PBS solution in four different types of microcentrifuge tubes as well as tissue culture plates and glass vials (see Materials and Methods for details of different vessels) for the nine steroids. All experiments were performed twice in duplicate; plots show each individual value with lines representing mean values. (C) Graphs of logs of fraction of steroid retained vs. log Kows for the nine steroids and six different vessels. Mean values ± standard deviations are shown. For all graphs, slopes of trendlines are different from zero (p < 0.0001).

Article Snippet: Because steroid adsorption to microcentrifuge tubes, both when steroid solutions are prepared for treatment of cells and when samples containing steroids are collected, could be a confounding factor in numerous experimental designs, we tested adsorption to four different types of polypropylene microcentrifuge tubes (Fisher, Costar, Eppendorf, and Axygen; see Materials and Methods for specific product details), three of which (Costar, Eppendorf, and Axygen) are specifically marketed as providing low binding or low retention of samples.

Techniques: Incubation

Journal: The Journal of steroid biochemistry and molecular biology

Article Title: Structure-dependent retention of steroid hormones by common laboratory materials

doi: 10.1016/j.jsbmb.2019.105572

Figure Lengend Snippet: (A) Fraction of steroid retained in Fisher microcentrifuge tubes after incubation times of 5 minutes, 30 minutes, 2 hours, 7 hours, and 24 hours for two steroids, pregnenolone and DHEA. Experiment was performed twice in duplicate and points on graph show mean ± SD. (B) Fraction of steroid retained in Fisher microcentrifuge tubes after 1 min. 6000 g centrifugation. Experiment was performed twice in triplicate and graph shows mean ± SD. (C) Fraction of steroid retained in TC plates after the same incubation times as in (A). Experiment was performed twice in duplicate and points on graph show mean ± SD.

Article Snippet: Because steroid adsorption to microcentrifuge tubes, both when steroid solutions are prepared for treatment of cells and when samples containing steroids are collected, could be a confounding factor in numerous experimental designs, we tested adsorption to four different types of polypropylene microcentrifuge tubes (Fisher, Costar, Eppendorf, and Axygen; see Materials and Methods for specific product details), three of which (Costar, Eppendorf, and Axygen) are specifically marketed as providing low binding or low retention of samples.

Techniques: Incubation, Centrifugation

Journal: The Journal of steroid biochemistry and molecular biology

Article Title: Structure-dependent retention of steroid hormones by common laboratory materials

doi: 10.1016/j.jsbmb.2019.105572

Figure Lengend Snippet: Fraction of pregnenolone (A) or DHEA (B) retained in Fisher microcentrifuge tubes, and fraction of pregnenolone (C) or DHEA (D) retained in TC plates, after one hour incubation in distilled water, D-PBS, serum-free culture media, or culture media with 10% charcoal-stripped fetal bovine serum. Experiments were performed twice in duplicate; plots show each individual value with lines representing mean values. For pregnenolone in tubes, retention from 10% CSS media was less than from all other solutions and retention from serum-free media was less than from distilled water or D-PBS (p < 0.001 for all comparisons, Tukey’s multiple comparison test after one-way ANOVA). For DHEA in tubes, retention from 10% CSS media was less than from all other solutions (p < 0.001 for 10% CSS media vs. distilled water or D-PBS; p = 0.004 for 10% CSS media vs. serum-free media) and retention from serum-free media was less than from distilled water (p = 0.005) or D-PBS (p = 0.002). For pregnenolone in TC plates, retention from 10% CSS media was less than from all other solutions and retention from serum-free media was less than from distilled water or D-PBS (p < 0.001 for all comparisons). For DHEA in TC plates, retention from 10% CSS media was less than from all other solutions (p < 0.001 for all comparisons) and retention from serum-free media was less than from distilled water (p = 0.01) or D-PBS (p = 0.003).

Article Snippet: Because steroid adsorption to microcentrifuge tubes, both when steroid solutions are prepared for treatment of cells and when samples containing steroids are collected, could be a confounding factor in numerous experimental designs, we tested adsorption to four different types of polypropylene microcentrifuge tubes (Fisher, Costar, Eppendorf, and Axygen; see Materials and Methods for specific product details), three of which (Costar, Eppendorf, and Axygen) are specifically marketed as providing low binding or low retention of samples.

Techniques: Incubation

Journal: The Journal of steroid biochemistry and molecular biology

Article Title: Structure-dependent retention of steroid hormones by common laboratory materials

doi: 10.1016/j.jsbmb.2019.105572

Figure Lengend Snippet: Fraction of pregnenolone or DHEA retained in Fisher microcentrifuge tubes after 1 hour incubation in D-PBS at concentrations of 2, 20, and 200 nM for each steroid. Experiment was performed twice in duplicate and graph shows mean ± SD. For pregnenolone across different concentrations, p = 0.43 from one-way ANOVA. For DHEA across different concentrations, p = 0.31 from one-way ANOVA.

Article Snippet: Because steroid adsorption to microcentrifuge tubes, both when steroid solutions are prepared for treatment of cells and when samples containing steroids are collected, could be a confounding factor in numerous experimental designs, we tested adsorption to four different types of polypropylene microcentrifuge tubes (Fisher, Costar, Eppendorf, and Axygen; see Materials and Methods for specific product details), three of which (Costar, Eppendorf, and Axygen) are specifically marketed as providing low binding or low retention of samples.

Techniques: Incubation

Journal: The Journal of steroid biochemistry and molecular biology

Article Title: Structure-dependent retention of steroid hormones by common laboratory materials

doi: 10.1016/j.jsbmb.2019.105572

Figure Lengend Snippet: Fraction of pregnenolone or DHEA retained in Fisher microcentrifuge tubes after 1 hour incubation in D-PBS at 4°C, 22°C, and 37°C. Experiment was performed twice in triplicate and graph shows mean ± SD. For both pregnenolone and DHEA, retention at 4°C was greater than at 22°C or 37°C (p < 0.001 for all comparisons, Tukey’s multiple comparison test after one-way ANOVA).

Article Snippet: Because steroid adsorption to microcentrifuge tubes, both when steroid solutions are prepared for treatment of cells and when samples containing steroids are collected, could be a confounding factor in numerous experimental designs, we tested adsorption to four different types of polypropylene microcentrifuge tubes (Fisher, Costar, Eppendorf, and Axygen; see Materials and Methods for specific product details), three of which (Costar, Eppendorf, and Axygen) are specifically marketed as providing low binding or low retention of samples.

Techniques: Incubation

Journal: The Journal of steroid biochemistry and molecular biology

Article Title: Structure-dependent retention of steroid hormones by common laboratory materials

doi: 10.1016/j.jsbmb.2019.105572

Figure Lengend Snippet: Fraction of pregnenolone collected in media, cell pellet or simulated pellet collection, and empty tube for one hour incubations of serum-free media with pregnenolone in Fisher microcentrifuge tubes with and without LNCaP prostate cancer cells (A) or HMC-1–8 breast cancer cells (B). Experiment was performed twice in triplicate (A) or three times in triplicate (B) and graphs shows mean ± SD. Retention in empty tubes was greater without cells than with cells for both cell lines (t-tests, p < 0.001).

Article Snippet: Because steroid adsorption to microcentrifuge tubes, both when steroid solutions are prepared for treatment of cells and when samples containing steroids are collected, could be a confounding factor in numerous experimental designs, we tested adsorption to four different types of polypropylene microcentrifuge tubes (Fisher, Costar, Eppendorf, and Axygen; see Materials and Methods for specific product details), three of which (Costar, Eppendorf, and Axygen) are specifically marketed as providing low binding or low retention of samples.

Techniques: