RODAC plates versus Dipslides for infallible hygiene control

RODAC plates versus dipslides: which is the best choice for hygiene control?

RODAC plates or dipslides are often used for hygiene control. Both are considered reliable methods for microbiological hygiene control, but there are also differences. In this blog, we explain the differences between these two methods, what the advantages and disadvantages are, and in which situations it is best to choose RODAC plates or dipslides.

What are RODAC plates?

RODAC (Replicate Organism Detection And Counting) plates are petri dishes with a spherical nutrient medium. By pressing the plate onto a surface, bacteria and fungi present are transferred to the medium. After incubation, you can precisely count the colonies. RODAC plates are the gold standard for quantitative microbiological monitoring of surfaces and are also frequently used, for example, to assess whether the hygiene of textiles meets agreed standards.

Benefits of RODAC Plates

• Quantitative and accurate: you determine the exact number of colony-forming units (CFU) per cm².
• Ideal for certification: Meets the requirements of hygiene audits and quality standards such as, for example, CERTEX and NEN-EN 14065 RABC (hygiene laundry seal of approval).
• Reproducible: Standard method, suitable for trend analysis and comparisons.
• Widely applicable: Perfect for hard, flat surfaces in laundry, food and healthcare industries, among others, i.c.w. with the application of Petrifilms for liquids.

Disadvantages of RODAC plates

• Less suitable for liquids or hard-to-reach/uneven surfaces.
• More vulnerable when transported.

What are dipslides?

Dipslides are plastic strips with a nutrient base on both sides. You can dip the dipslide into a liquid or press it onto a surface. After incubating the dipslides in an incubator , you visually read the result with a reference chart, determining whether there is limited, medium or strong growth. Dipslides are especially popular for quick, indicative hygiene checks.

Benefits of dipslides

• Quick and very easy to use: Apply immediately on site.
• Versatile: Suitable for surfaces as well as liquids, even in hard-to-reach areas.
• Cost-effective: Ideal for frequent screening and trend monitoring.
• Safe transportation: Less fragile than petri dishes.
• Dual analysis possible: Two types of nutrient media on one slide, for example, for bacteria AND fungi.
• Several months shelf life: Under the right conditions, dipslides can be kept for several months after production. Depending on the type of feeding medium, this can be as long as 6 to 9 months. With this, the shelf life is often longer than that of RODAC plates.

Disadvantages of dipslides

• Semi-quantitative: Results are indicative.
• Smaller sample area: Less representative with large areas.
• Visual interpretation: Reading is more subjective than counting colonies with RODAC plates.

Difference between RODAC plates and dipslides

When do you choose RODAC plates?

RODAC plates are the best choice when:

• You have to meet certification requirements or hygiene audits.
• You need quantitative, reproducible results.
• You work with hard, flat surfaces.

When are dipslides appropriate?

Dipslides are ideal when:

• You want to monitor hygiene quickly and easily.
• You want to perform trend analysis, where the exact number of CFU is less relevant.
• You are looking for a cost-effective solution for frequent checkups.

CCD: specialist in RODAC plates and dipslides

At CCD, we have for many years supplied RODAC plates to companies that need to meet the strictest hygiene standards. We regularly train employees of our customers to properly perform sampling using RODAC plates and Petrifilms , analyze them and interpret the results. In this way, they learn not only how to determine current hygiene, but also how to improve it further. With the addition of dipslides to our range, we now also offer a practical solution for quick, indicative hygiene checks in a variety of sectors.

Unsure which method best suits your organization? Contact us for a no-obligation consultation.

With RODAC plates you meet the highest requirements, with dipslides you easily monitor daily hygiene. This way, CCD offers the right solution for every situation!