Suitability of Invertebrate and Vertebrate Cells in a Portable Impedance-Based Toxicity Sensor: Temperature Mediated Impacts on Long-Term Survival

Abstract

Standard Form 298 (Rev. 8/98) REPORT DOCUMENTATION PAGEPrescribed by ANSI Std. Z39.18 Form Approved OMB No. 0704-0188The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing the burden, Using ECIS (electric cell-substrate impedance sensing) to monitor the impedance of vertebrate cell monolayers provides a sensitive measure of toxicity for a wide range of chemical toxicants. One major limitation to using a cell-based sensor for chemical toxicant detection in the field is the difficulty in maintaining cell viability over extended periods of time prior to use. This research was performed to identify cell lines suitable for ECIS-based toxicity sensing under field conditions. A variety of invertebrate and vertebrate cell lines were screened for their abilities to be stored for extended periods of time on an enclosed fluidic biochip with minimal maintenance. Three of the ten cell lines screened exhibited favorable portability characteristics on the biochips. Interestingly, all three cell lines were derived from ectothermic vertebrates, and the storage temperature that allowed long-term cell survival on the enclosed fluidic biochips was also at the lower end of reported body temperature for the organism. Future work with the ectothermic vertebrate cells will characterize their sensitivity to a wide range of chemical toxicants. Using ECIS (electric cell-substrate impedance sensing) to monitor the impedance of vertebrate cell monolayers provides a sensitive measure of toxicity for a wide range of chemical toxicants. One major limitation to using a cell-based sensor for chemical toxicant detection in the field is the difficulty in maintaining cell viability over extended periods of time prior to use. This research was performed to identify cell lines suitable for ECIS-based toxicity sensing under field conditions. A variety of invertebrate and vertebrate cell lines were screened for their abilities to be stored for extended periods of time on an enclosed fluidic biochip with minimal maintenance. Three of the ten cell lines screened exhibited favorable portability characteristics on the biochips. Interestingly, all three cell lines were derived from ectothermic vertebrates, and the storage temperature that allowed long-term cell survival on the enclosed fluidic biochips was also at the lower end of reported body temperature for the organism, suggesting that reduced cellular metabolism may be essential for longterm survival on the biochip. Future work with the ectothermic vertebrate cells will characterize their sensitivity to a wide range of chemical toxicants to determine if they are good candidates for use in a field portable toxicity sensor.

Characterization of the continuous skin fibroblastoid cell line, WE‐skin11f, from walleye (Sander vitreus)

“…WE‐skin11f cells survived and grew at different temperatures that reflected the thermobiology of walleye (Hokanson, ) and was similar to other walleye cell lines. At 26°C, proliferation was best, and at 4°C, proliferation was absent but cells remained viable (Curtis et al, ; Vo, Bender, et al, ; Vo et al, ).…”

“…Cultures were then treated with either 0.01% ethanol (vehicle control) or 100 ng/ml cortisol, and impedance in ohms was recorded. Impedance measurements (at 16,000 Hz) were made with the ECIS 1600 analyzer (Applied BioPhysics) as previously described by Curtis et al (). Data were normalized to time‐zero measurements and recorded as normalized impedance.…”

Differential viral haemorrhagic septicaemia virus genotype IVb infection in fin fibroblast and epithelial cell lines from walleye, Sander vitreus (Mitchill), at cold temperatures

“…Previously, the development of WE‐cfin11e was described as part of a paper in which many vertebrate cell lines were compared for their suitability to be used in a portable impedance‐based toxicity sensor (Curtis et al . ). WE‐cfin11e was a superior cell line for that purpose but was not characterized further and so is characterized here.…”

“…Cell lines were maintained routinely at 26 °C in L‐15 medium (Hyclone) with 5% to 15% foetal bovine serum (FBS; Hyclone) (Curtis et al . ; Vo et al . ).…”

A portable chemical toxicity biochip based on electronic enzymatic monitoring of cytotoxic effects on fish cells

“…A number of researchers have employed mammalian cells for cytotoxicity testing of key environmental toxicants including disinfection byproducts, pesticides and heavy metals [16][17][18][19]. However, one of the major challenges in the development of portable mammalian cell biosensors for on-site analysis is the requirement for growth at 37 • C in a 5% CO 2 atmosphere and the need for frequent medium changes and subculture [20]. As an alternative, a number of groups have employed fish cells as a biological indicator [21][22][23][24] with electric cell substrate impedance sensing (ECIS) or amperometric measurement of redox mediators used to assess changes in cell viability upon toxicant exposure.…”