Petri Dish Medium Fill Level for Filter Handling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for microbiological analysis of liquids using membrane filtration are cumbersome due to the sensitivity of filters and the need for larger Petri dishes, which consume more materials and space, especially in high-throughput laboratories.
Innovation Solution
A Petri dish filled almost completely with medium, allowing filters to be placed closer to the edge without obstruction, reducing handling difficulties and enabling the use of smaller dishes, along with a method involving filtration, incubation, and evaluation of germ growth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If filters are placed on Petri dishes with sufficient margin from the edge, then filters can be properly positioned on the medium, but the Petri dish diameter must be significantly larger than the filter diameter
Solution Approach 1:
The patent changes the parameter of medium filling level from partial filling to filling almost to the brim (within 1-3 mm of the edge). This parameter change allows the filter to be placed closer to the edge without obstruction, enabling the use of smaller Petri dishes while maintaining proper filter positioning and accessibility.
2Ease of operation
If Petri dishes are filled almost completely with medium, then filter handling is simplified and dish diameter can be reduced, but the risk of medium overflow or contamination during lid closing increases
Solution Approach 1:
The patent specifies that the medium should be filled to a level that is almost to the brim but maintains a small clearance (1-3 mm) from the edge. This preliminary positioning of the medium level prevents overflow during lid closing while still allowing the filter to be placed close to the edge, thus simplifying filter handling without compromising medium stability.
3Ease of operation
If larger Petri dishes are used to accommodate filter placement, then filters can be easily positioned, but material consumption and space requirements increase
Solution Approach 1:
By changing the medium filling parameter to almost complete filling (within 1-3 mm of the edge), the patent enables the use of smaller Petri dishes that match the filter diameter more closely. This reduces the amount of medium required per dish and decreases the space needed for incubation, while still allowing easy filter positioning.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Simplifies filter handling, reduces material and space requirements, and allows for more efficient microbiological analysis by enabling easier placement and incubation of filters in a space-saving manner.
Implementation Method 1
a) filtration of the liquid or gas through a filter
Implementation Method 2
The filter preferably has an exclusion limit between 0.2 and 0.45 μm
Implementation Method 3
The germs that may have been filtered out of the liquid receive nutrients via the agar, which stimulate growth so that the germs multiply
Implementation Method 4
The germs that may have been filtered out of the liquid receive nutrients via the agar, which stimulate growth so that the germs multiply and can be identified or counted
Data Source
AI summary
The invention relates to a medium-filled Petri dish into which filters can be particularly easily inserted, and to a method for the microbiological examination of liquids or gases by filtration and incubation of the filters in said Petri dishes.