# A rapid method of evaluating cytotoxic drug efficacy using sub-cellular fluctuation imaging

## TL;DR

This paper introduces a fast, label-free method to test how well cancer drugs kill cells by observing changes in sub-cellular activity.

## Contribution

The study presents a novel rapid method using sub-cellular fluctuation imaging to assess drug efficacy within 3 hours.

## Key findings

- SCFI detected drug effects within 1 to 3 hours, except in drug-resistant cell lines.
- The method distinguished treated and untreated cells in 3 to 4 hours without overnight incubation.
- SCFI reliably identifies cytotoxic drugs faster than existing methods.

## Abstract

Determining whether potential cancer therapies effectively kill cancer cells is important for informing effective therapeutic choice for patients. Here we describe a rapid label-free method for testing drug efficacy in vitro that evaluates cellular viability from sub-cellular fluctuation imaging (SCFI). We used staurosporine and paclitaxel as known cytotoxic drugs at different concentrations, and four different human cancer-derived cell lines: PC3 (prostate), Caco-2 (colorectal), Calu-3 (lung) and A549 (lung). Both drugs caused a rapid decrease in sub-cellular fluctuations within 1 to 3 h except when the specific cell line was known to be resistant to one of the drugs. We also demonstrated that the method is able to differentiate between treated and untreated PC3 cells within 3 to 4 h after cells have been plated, thus eliminating the need for overnight incubation, and further decreasing the total time needed to evaluate drug efficacy. SCFI is therefore able to identify reliably if drugs are cytotoxic within 3 h of addition, which is considerably faster than current commonly used techniques.