Karen Rojas Perez - Academia.edu (original) (raw)

Karen Rojas Perez

Uploads

Papers by Karen Rojas Perez

Research paper thumbnail of Breakthrough Listen Search for Technosignatures toward the Kepler-160 System

Research Notes of the AAS, 2020

Research paper thumbnail of Revisiting 23-iodospirostanes. New facts and full characterization

Research paper thumbnail of Synthesis of nanomaterials in microemulsions: formation mechanisms and growth control

Current Opinion in Colloid & Interface Science, 2003

Research paper thumbnail of New methodological improvements in the Microtox® solid phase assay

Chemosphere, 2012

The classic Microtox® solid phase assay (MSPA) based on the inhibition of light production of the... more The classic Microtox® solid phase assay (MSPA) based on the inhibition of light production of the marine bacteria recently renamed Aliivibrio fischeri suffers from various bias and interferences, mainly due to physico-chemical characteristics of the tested solid phase. To precisely assess ecotoxicity of sediments, we have developed an alternative method, named Microtox® leachate phase assay (MLPA), in order to measure the action of dissolved pollutants in the aqueous phase. Two hypotheses were formulated to explain the observed difference between MSPA and MLPA results: a real ecotoxicity of the solid phase or the fixation of bacteria to fine particles and/or organic matter. To estimate the latter, flow cytometry analyses were performed with two fluorochromes (known for their ability to stain bacterial DNA), allowing correction of MSPA measurements and generation of new (corrected) IC50. Comparison of results of MLPA with the new IC50 MSPA allows differentiating real ecotoxic and fixation effect in classic MSPA especially for samples with high amount of fines and/or organic matter.

Research paper thumbnail of Breakthrough Listen Search for Technosignatures toward the Kepler-160 System

Research Notes of the AAS, 2020

Research paper thumbnail of Revisiting 23-iodospirostanes. New facts and full characterization

Research paper thumbnail of Synthesis of nanomaterials in microemulsions: formation mechanisms and growth control

Current Opinion in Colloid & Interface Science, 2003

Research paper thumbnail of New methodological improvements in the Microtox® solid phase assay

Chemosphere, 2012

The classic Microtox® solid phase assay (MSPA) based on the inhibition of light production of the... more The classic Microtox® solid phase assay (MSPA) based on the inhibition of light production of the marine bacteria recently renamed Aliivibrio fischeri suffers from various bias and interferences, mainly due to physico-chemical characteristics of the tested solid phase. To precisely assess ecotoxicity of sediments, we have developed an alternative method, named Microtox® leachate phase assay (MLPA), in order to measure the action of dissolved pollutants in the aqueous phase. Two hypotheses were formulated to explain the observed difference between MSPA and MLPA results: a real ecotoxicity of the solid phase or the fixation of bacteria to fine particles and/or organic matter. To estimate the latter, flow cytometry analyses were performed with two fluorochromes (known for their ability to stain bacterial DNA), allowing correction of MSPA measurements and generation of new (corrected) IC50. Comparison of results of MLPA with the new IC50 MSPA allows differentiating real ecotoxic and fixation effect in classic MSPA especially for samples with high amount of fines and/or organic matter.

Log In