Microbiology

Petri Dishes

<h2 data-section-id="8oh3r3" data-start="0" data-end="36">What Are Laboratory Petri Dishes?</h2>
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A petri dish is a shallow, circular, flat-bottomed lidded container used for culturing microorganisms such as bacteria and fungi on solid agar-based growth media. The standard laboratory format is 90 mm diameter &times; 15 mm depth, which provides an optimal surface area for colony isolation, enumeration, and antimicrobial testing. First introduced by Julius Richard Petri in 1887, the petri dish remains one of the most essential tools in microbiology for applications such as streak-plate isolation, colony-forming unit (CFU) counting, antimicrobial susceptibility testing (Kirby-Bauer method), environmental monitoring, and general microbial identification. Disposable polystyrene petri dishes are manufactured under cleanroom conditions, gamma sterilized (SAL 10⁻⁶), and produced as DNase/RNase-free consumables for contamination-sensitive workflows. Polystyrene dishes should not be autoclaved, as high heat can deform the material; reusable glass dishes are used when heat sterilization or chemical resistance is required.
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<h2 dir="ltr">What you will find: </h2>
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Optical clarity for distortion-free observation
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Ventilated lids for airflow with minimal condensation
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Stable, stackable design for safe handling
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Smooth surface for easy inoculation
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Sterile and available in multiple sizes
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<h2 data-section-id="jngrvt" data-start="1064" data-end="1093">How to Choose Petri Dishes</h2>
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Size
The 90 mm petri dish is the global standard used in most clinical and research laboratories because it fits standard incubator racks and supports typical agar volumes of 15&ndash;20 mL. Smaller 60 mm dishes are used for teaching exercises, limited sample volumes, or cost-efficient plating, while larger 150 mm dishes provide increased surface area for dense cultures, slow-growing organisms, or specialized susceptibility testing applications.
Lid: Vented vs. Non-Vented
Vented lids allow controlled gas exchange, helping maintain aerobic conditions and reduce condensation buildup during incubation. Non-vented lids are used when a sealed environment is required, such as in anaerobic systems, transport conditions, or moisture-sensitive applications where evaporation must be minimized.
Material
Polystyrene (PS) is the most commonly used material for disposable microbiology petri dishes due to its clarity, low cost, and consistent manufacturing quality. Polypropylene (PP) dishes offer higher heat resistance and can withstand autoclave conditions, but they are less optically clear. Borosilicate glass petri dishes are reusable, chemically resistant, and suitable for workflows requiring repeated sterilization or harsh chemical exposure.
Surface Treatment
Non-treated polystyrene dishes are used for standard bacterial and fungal culture. Tissue culture (TC)-treated dishes have a surface modification that promotes cell attachment and are intended for mammalian cell culture applications, not routine microbiology work. Selecting the correct surface treatment ensures accurate microbial growth and prevents unnecessary cost.
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<h2 data-section-id="1jl751w" data-start="3400" data-end="3425">Specifications Context</h2>
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Modern laboratory petri dishes are manufactured from high-grade virgin polystyrene under controlled cleanroom conditions to ensure consistency in agar surface quality and colony morphology. Stacking rings on the dish base allow airflow and thermal equilibration during incubation. In standardized microbiology methods such as CLSI, EUCAST, and AOAC protocols, 90 mm petri dishes are the preferred format for CFU counting and antimicrobial susceptibility testing. A typical agar volume of 15&ndash;20 mL per 90 mm plate ensures consistent depth and reliable diffusion characteristics for microbiological assays. Together, petri dishes, inoculating loops, and culture media form the foundation of routine bacterial culture workflows in clinical and research laboratories.
Ready to upgrade your incubation standards? Don&rsquo;t let uneven growth or condensation cloud your data. <a href="https://mbpinc.net/contact-us">Reach out to the MBP team today</a> to secure the high-performance Petri dishes your cultures deserve.

Datsheet

65mm RODAC Dish

65mm RODAC Dish, 20/pk, 500/cs

722011 by NEST Scientific is a 65 mm RODAC contact dish manufactured from USP Class VI virgin polystyrene, with a convex bottom and grid lines for direct colony counting after surface sampling. E-beam sterilized to SAL 10⁻⁶, DNase/RNase-free, and lot-tested free of BSE/TSE agents. Manufactured in an ISO 7 cleanroom under ISO 13485:2016 and cGMP (21 CFR Part 820). Ships 20 per pack, 500 per case.

Manufacturer

Innoculating Needles/Loops

<h2 data-section-id="y6ykl1" data-start="0" data-end="42">What Are Inoculating Loops and Needles?</h2>
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Inoculating loops and needles are essential microbiology tools used to transfer microorganisms between culture media, agar plates, broth tubes, and other laboratory growth systems. An inoculating loop features a small circular end designed to hold a defined volume of liquid culture, while an inoculating needle has a straight tip used for picking colonies and inoculating semi-solid media. Modern disposable versions are manufactured from sterile polypropylene or polystyrene and have largely replaced reusable metal loops in many laboratories, helping reduce cross-contamination risks and eliminating the need for flame sterilization between samples. These tools are widely used in clinical microbiology, research laboratories, pharmaceutical testing, food microbiology, and environmental monitoring applications.
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<h2 dir="ltr">What you will find:<a href="https://mbpinc.net/consumables/microbiology/innoculating-needles/loops" title="Inoculating Needles &amp; Loops"></a></h2>
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Smooth loops for streaking without agar damage
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Fine-point needles for precise colony picking
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Sterile disposable options for safe, aseptic use
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Heat-resistant wire loops for repeated sterilization
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Ergonomic grip for better control and reduced fatigue
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<h2 data-section-id="x4zq8w" data-start="861" data-end="907">How to Choose Inoculating Loops and Needles</h2>
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Volume: 1 &micro;L vs. 10 &micro;L
The choice of loop volume depends on the application. A 1 &micro;L calibrated loop is commonly used for quantitative urine cultures and other procedures where accurate sample volume directly affects colony counts and microbial enumeration. A 10 &micro;L loop is the standard option for routine streak plating, subculturing, and general microorganism transfer where larger sample volumes are beneficial.
Rigidity: Flexible PP vs. Rigid PS
Flexible polypropylene loops are designed to glide smoothly across agar surfaces, minimizing damage to the media during streaking procedures. Rigid polystyrene loops and needles provide greater control when inoculating broth cultures, retrieving colonies, or performing stab inoculations in semi-solid agar. Many laboratories keep both flexible and rigid options available to accommodate different microbiological techniques.
Calibration and Lot Certification
For quantitative microbiology applications, calibrated loops should be selected to ensure consistent volume delivery. Certified loops undergo validation testing to verify that they deliver the specified sample volume accurately. This level of quality assurance is particularly important in clinical laboratories performing urine cultures and other quantitative microbial analyses.
Packaging Format
Individually packaged sterile loops provide maximum sterility assurance and are ideal for low-volume testing environments. Bulk-packaged sterile loops offer a more economical solution for high-throughput laboratories where large quantities are used daily. The choice depends on workflow requirements, usage frequency, and laboratory contamination-control practices.
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<h2 data-section-id="1jl751w" data-start="3179" data-end="3204">Specifications Context</h2>
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Disposable inoculating loops and needles are typically manufactured from medical-grade polypropylene or polystyrene and supplied sterile for immediate use. Standard loop sizes are designed to deliver consistent volumes and feature smooth surfaces that support accurate sample transfer. Many calibrated loops are tested using recognized verification methods and supplied with lot-specific certification to support laboratory quality assurance requirements. Disposable plastic loops are now widely used across clinical, academic, pharmaceutical, and industrial microbiology laboratories due to their convenience, consistency, and reduced contamination risk compared with reusable metal alternatives.
For product selection or technical guidance, <a href="https://mbpinc.net/consumables/microbiology/innoculating-needles/loops" title="connect with the Molecular Biology Products Inc. (MBP) team.">connect with the Molecular Biology Products Inc. (MBP) team.</a>

Inoculating Needle

Inoculating Loop

Inoculating Needles and Loops Specifications

Nest Inoculating Loops & Needles

716001 by NEST Scientific is a sterile straight-tip inoculating needle for stab cultures, motility testing, anaerobic culture inoculation, and semi-solid media transfer. Hydrophilic polypropylene, flexible handle, white, EtO sterilized, individually wrapped. Part of the NEST inoculating family alongside 1 µL (717101) and 10 µL (718201) loops. 400/pk, 4,000/cs.

Inoculating Needle, White, Individually Wrapped, sterile 400/pk, 4000/cs

1µl Inoculating Loop, Blue, Individually Wrapped, sterile 400/pk, 4000/cs

10µl Inoculating Loop, Yellow, Individually Wrapped, sterile 400/pk, 4000/cs

Nest Polystyrene L shaped Spreader

711001 by NEST Scientific is a sterile L-shaped cell spreader made from medical-grade polystyrene, individually wrapped for single-use spread-plate technique in microbiology. E-beam sterilized to SAL 10⁻⁶, non-pyrogenic, DNase/RNase-free, BSE/TSE-free. Smooth flat surface minimizes uneven application. 200/pk, 2,000/cs.

Nest Scientific Petri Dish, Sterile

Nest Scientific Petri Dishes

The 706011 by NEST Scientific is a 35 &times; 12 mm non-treated polystyrene petri dish, sterile and DNase/RNase-free, with a three-vent lid for passive gas exchange and a ridged base for secure stacking. Supplied 20 per pack, 500 per case. Suitable for bacterial, fungal, and general cell biology culture where TC surface treatment is not required.