Biofilms are biological aggregates consisting of microorganisms and extracellular polysaccharides that can exist in many environments. The microorganisms in biofilms are highly resistant to antibiotics; therefore, research into medicines and food ingredients that have anti-biofilm activities is a growing area.
Our assay kits for the quantitative measurements of biofilm formation/inhibition of biofilm formation (Biofilm Formation Assay Kit) and anti-biofilm drug efficacy (Biofilm Viability Assay Kit) adopted a protocol which is designed to use the peg plate from biofilm formation. Our assay kits combined all the necessary components into each package.
Feature 1: Measurement time can be significantly shortened.
In existing methods, biofilms are formed on the bottom of the well of a microplate, and additional work is required to change microbial culture media and wash sample several times before and after staining. However, our assay kits allow you to form biofilms on the pegs attached to the plate's lid. Media change and staining process can be done simply by transferring the lid; therefore, our assay kits are very easy to use.
Feature 2: Our assay kits can reduce measurement variation.
In existing methods, biofilm formation occurs on the bottom of the well of a microplate, which made biofilm easier to peel off because of the processes such as washing. This causes measurement variation, and this measurement variation was an issue for the quantification of biofilm. Our assay kits allow you to form biofilms on the pegs attached to the plate's lid and make it possible to avoid peeling off biofilm which occurs during the process of the formation.
Two different types of assay kits for different purposes.
We offer two types of assay kits that measure the amount of biofilm formation or the metabolic activities of live microorganisms within biofilms by using the same measurement method. You can select the one that best suits your needs.
Selection of 2 types of assay kits
*Conditions on biofilm formation vary according to microbial species and strains. When you need to examine these conditions, we first recommend you use the Biofilm Formation Assay Kit.
*The Biofilm Formation Assay Kit is a product developed together with Fukuoka Industrial Technology Center.
Example of measurement
Indicators for drug-mediated inhibition of biofilm formation or antimicrobial effect of biofilms include MBIC (minimum biofilm inhibitory concentrations) and MBEC (minimum biofilm eradication concentrations). MBIC and MBEC of S. aureus were measured using each kit.
[How to use – Quick Tutorial]
Q1. What is the incubation time after addition of staining reagent?
A1. Staining time differs depending on microbial species or metabolic activities.
In the first experiment, we recommend about 24 hours of incubation, along with the constant checking of absorbance. Examples of using S.aureus and S.mutans are shown in Figures 2 and 3 in the technical manual. Please refer to these examples.
Q2. Is it possible to use filters other than a 450 nm filter?
2. You can use filters ranged from 440 to 480 nm for measurement.
Q3. When I evaluate inhibition of biofilm formation and anti-biofilm drug efficacy, what is the approximate amount of biofilm formation required for experiment?
A3. In the Biofilm Formation Assay Kit (Product code: B601), please consider the amount of biofilm formation as a rough indication when a value of absorbance (590 nm) for crystal violet solution obtained after the final step is greater than 0.5.
Q4. What types of microbial species have been tested?
A4. Dojindo Laboratories has evaluated the following microbial species that formed biofilms using the Biofilm Formation Assay Kit (Product code: B601) and the Biofilm Viability Assay Kit (this product).
Please refer to the technical manual, in terms of culture conditions for the above microbial species, experimental examples, etc.