5 files

Log Reduction Measurements of Soft Solids (Chitosan and Polyacrylic Acid Gel Particles) on a Bio-Surface (VITRO-SKIN)

posted on 2024-06-28, 11:19 authored by Balasubramanian Vasanthakumar, Brij M. Moudgil
The provided CSV file titled "Log reduction of E.coli in VITROSKIN" serves as a repository for the raw data utilized to generate the plots depicting the reduction of E. coli cells across three experimental trials. The trials investigated the efficacy of chitosan, polyacrylic acid, and soft solids in reducing E. coli populations within a bio-surface solution environment. The agar plate count method, which involved serial dilution techniques, was utilized to enumerate bacterial populations. The efficacy of bacterial removal was expressed logarithmically as log10 bacterial removal using Eqn. (1):


log10 bacterial removal = log10 (Initial bacterial inoculum on skin) − log10 (bacteria remaining on skin) (1)

The results were presented in terms of the total number of bacteria recovered (CFU) on a logarithmic scale.

The CSV file also provides data on the average log reduction of E. coli cells and their corresponding standard deviations for each sample comprising individual polyelectrolytes or polyelectrolyte mixtures (soft solids). Specifically, Columns B and D contain data pertaining to the average log reduction of E. coli cells in the presence of individual polyelectrolytes, with Column H serving as the standard X-axis reference. Column F presents the average log reduction of E. coli cells in the presence of polyelectrolyte mixtures (soft solids), aligned with Column I as the shared X-axis.

In addition, CSV files 4–6 represent separate data obtained from Chitosan–Vitroskin, PAA–Vitroskin, and Complex–Vitroskin experiments, respectively.

Measurement condition

The cell viability in the suspension was determined via the agar plate count (serial dilution) method after incubating at 37°C overnight before counting colony-forming units (CFU). Following this incubation period, colony-forming units (CFU) were enumerated to gauge the extent of bacterial removal. The results were then articulated in logarithmic scale, indicating the total count of bacteria eradicated, as per the equation provided earlier.

Experimental condition

The sample, comprising polyelectrolytes or polyelectrolyte mixtures, was evenly spread across a 1 cm^2 area of pre-hydrated skin substrate and allowed to air-dry at room temperature for 30 minutes. Subsequently, the coated skin substrate was exposed to a bacterial suspension containing 10^6 colony-forming units (CFU) per milliliter, followed by an additional drying period of 20 minutes.

To recover any remaining bacteria bound to the substrate, the skin substrates were then neutralized using D/E broth and subjected to vortexing at 3000 rpm (150×g) for continuous agitation lasting 30 seconds. This rigorous process ensured the efficient retrieval of bacteria adhered to the substrate for subsequent analysis.


I/UCRC: Proposal to Establish a Joint NSF I/UCR Center for Particulate Systems and Surfactants

Directorate for Engineering

Find out more...


Corresponding author email address



© 2024 The Author(s)

Usage metrics

    KONA Powder and Particle Journal



    Ref. manager