What is a cell culture dish?

A cell culture petri dish is a common disposable laboratory consumable used specifically for culturing cells in vitro. It is typically made of transparent polystyrene (PS) and undergoes a special surface treatment to facilitate cell attachment and growth.

Outwardly, a cell culture dish is a shallow, round dish with a flat bottom. The bottom provides a uniform distribution of cells, and the lower rim facilitates liquid manipulation and microscopic observation. Key features include:

• Excellent transparency—facilitates direct observation of cell status under a microscope.
• Surface treatment—Most culture dishes have a hydrophilic surface treatment, suitable for adherent cell growth; untreated surfaces are also available, commonly used for suspension cell culture.
• Various formats—suitable for experiments of varying scales, from small-scale drug screening to large-scale cell expansion.
• Sterile packaging—single-use, preventing cross-contamination.

Applications include: basic cell biology research, cancer model development, stem cell culture, transfection experiments, drug sensitivity testing, and more.

What are the main uses of microbiology petri dish?

The main purpose of a cell culture dish is to provide a controlled, sterile platform for cell growth and experimentation in vitro. It is not only one of the most common laboratory consumables, but also an indispensable tool in cell biology, medical research, and biopharmaceuticals. Specific uses include:

• Cell Expansion and Maintenance: Provides a growth environment for adherent cells (such as fibroblasts and tumor cell lines) or suspension cells, enabling researchers to maintain cell lines long-term in vitro.
• Observation of Cell Morphology and Behavior: The transparent bottom facilitates microscopic observation, allowing direct monitoring of cell morphology, attachment, proliferation rate, and apoptosis.
• Transfection and Gene Manipulation Experiments: Commonly used for transfection with plasmids, siRNA, and viruses to study gene expression, signaling pathways, or the effects of gene knockout/knockin.

• Drug and Toxicology Research: In drug screening, anti-tumor drug development, and antiviral drug development, culture dishes are used to evaluate the effects of drugs on cell survival, proliferation, and metabolism.

• Cell Differentiation and Regenerative Medicine Research: Stem cells can be induced to differentiate into specific cell types in culture dishes, which is used in tissue engineering and regenerative medicine.

• Experimental Model Development: Tumor, infection, or immunological models are established by culturing cells in vitro to study disease mechanisms.

• Basic Teaching and Research Training: In universities and research institutions, culture dishes are also commonly used for introductory cell culture experiments and teaching demonstrations.

What are the classifications of cell culture dishes?

• Depending on their purpose, Petri dishes can be divided into cell culture dishes and bacterial culture dishes.
• Depending on the material they are made of, they can be divided into plastic and glass dishes.
• Based on their size, Petri dishes are typically categorized into diameters of 35mm, 60mm, 90mm, and 150mm. 35mm or 60mm dishes save reagents and are suitable for early screening and small-scale experiments. 100mm or 150mm dishes facilitate amplification and collection.
• Depending on the cultured cells, it can be divided into TC treatment and non-TC treatment.TC-treated culture dishes are suitable for adherent cells, while non-TC-treated dishes are suitable for suspension cells.

Why are bacterial culture dishes 90mm, while cell culture dishes are commonly used to be 100mm?

• Standardization and usage differences

The size of bacterial culture dishes is often closely related to the testing method. For example, national standards (such as GB5750-2006) stipulate that total coliform bacteria testing requires the use of 90mm dishes, as they are compatible with membrane filter methods and facilitate quantitative colony counts. Furthermore, 90mm dishes are also commonly used for microbial sampling (such as airborne bacteria and surface contact plates), as the smaller diameter is more suitable for even distribution of specific culture media or for spreader methods.

The 100mm petri dish was also chosen based on experimental requirements. Cell growth requires a large surface area to support adherent growth. The base area of a 100mm dish is approximately 56 cm², providing ample space for cells. Furthermore, it can accommodate 10-15ml of culture medium, a sufficient volume to meet the nutritional needs of cell expansion.

Furthermore, with the increasing automation of laboratories, the 100mm format offers improved compatibility with many automated laboratory equipment, such as media dispensing systems. This allows for more efficient operations in cell experiments using 100mm dishes, reduces human error, and promotes greater precision and efficiency in cell experiments.

• Physical fit differences

Bacterial cultures often require inversion. The 90mm size is more portable and reduces the risk of spillage and contamination. Furthermore, the shallow design of the 90mm dish facilitates agar solidification and colony counting.

Cell culture media must cover the bottom of the dish, so the 100mm depth and capacity are more optimal, ensuring that cells are grown in sufficient medium.

• Production and cost factors

100mm culture dish molds are highly versatile, allowing for cost-effective mass production. Furthermore, academic literature and experimental protocols generally utilize the 100mm format, prompting manufacturers to prioritize production. 90mm, on the other hand, is primarily used in specific testing areas (such as medical and environmental monitoring), and fragmented demand has led to less widespread adoption.

Petri dishes for cell culture require plasma surface treatment (TC treatment) to enhance adherence, and the 100mm format has a more mature process. Bacterial culture dishes, on the other hand, are more concerned with sterilization resistance, and 90mm glass is more commonly used.

What is the difference between ring-grip and non-ring-grip cell culture dishes?

1. Differences in Appearance and Structure

• Grip-ring Petri dishes: A thickened or raised “gripping ring” is designed on the lid or rim of the dish. This structure allows researchers to place and retrieve the dish without directly touching the main body, providing a more secure grip.
• Non-grip-ring Petri dishes: They have smooth edges and lack an additional ring, making them appear simpler. However, handling requires greater care to avoid slipping or contamination.

2. Differences in User Experience

• Ring-grip type: More convenient to operate, especially when operated one-handed under sterile conditions (such as in a clean bench), making it easier to open and close culture dishes. It’s less prone to slipping, reducing the risk of spilling culture medium. It’s suitable for experiments requiring frequent observation or manipulation.
• Non-ring-grip type: Relatively lower cost and more economical. It’s suitable for basic experiments with frequent single-use. However, it requires higher operator skill and can easily cause contamination or slippage if not handled properly.

3. Differences in Application Scenarios

• Ring-grip culture dishes are commonly used in experiments requiring high sterility and ease of use, such as drug screening, cell microscopy, or experiments requiring frequent culture medium changes.
• Non-ring-grip culture dishes are primarily used for routine cell culture, teaching experiments, or research scenarios where ease of use is less critical.

How many cells can be harvested from a confluent monolayer of 35 mm, 60 mm, 100 mm, or 150mm cell culture dishes?

The following estimates provide an approximate yield of cells that can be harvested from confluent monolayers of 35 mm, 60 mm, 100 mm, and 150 mm culture dishes, based on three commonly used adherent cell confluence densities: a conservative value of 2.0×10⁴ cells/cm², a typical value of 5.0×10⁴ cells/cm², and a high value of 1.0×10⁵ cells/cm². These estimates are based on the available surface area of the dish bottom (actual manufacturer-specified available area may vary slightly) and do not account for cell attachment and harvest losses (corrections for this are described below). The approximate dish bottom areas used are: 35 mm ≈ 9.62 cm²; 60 mm ≈ 28.27 cm²; 100 mm ≈ 78.54 cm²; and 150 mm ≈ 176.71 cm².

• Based on a conservative density of 2.0×10⁴ cells/cm²:

1. 35 mm dish: Approximately 192,400 cells can be harvested.
2. 60 mm dish: Approximately 565,500 cells can be harvested.
3. 100 mm dish: Approximately 1,570,800 cells can be harvested.
4. 150 mm dish: Approximately 3,534,300 cells can be harvested.

• Based on a commonly used density of 5.0×10⁴ cells/cm² (this range is often used as the target confluence density for many adherent cell cultures):

1. 35 mm dish: Approximately 481,100 cells can be harvested.
2. 60 mm dish: Approximately 1,413,700 cells can be harvested.
3. 100 mm dish: Approximately 3,926,990 cells can be harvested.
4. 150 mm dish: Approximately 8,835,700 cells can be harvested.

• Calculated at a slightly higher density of 1.0×10⁵ cells/cm² (for small cell lines or short-term high-density culture):

1. 35 mm dish: Approximately 962,100 cells can be harvested.
2. 60 mm dish: Approximately 2,827,400 cells can be harvested.
3. 100 mm dish: Approximately 7,853,980 cells can be harvested.
4. 150 mm dish: Approximately 17,671,500 cells can be harvested.

Correction recommendations for the actual number of cells that can be recovered (must be considered):

• The above values assume that 100% of cells are viable and successfully recovered. In reality, factors such as attachment rate, cell death, and losses from enzymatic digestion or scraping often affect these values. A common practical recommendation is to use an attachment/viability rate of 70–90% and a harvest recovery rate of 60–90%. For example, if we assume an 80% attachment rate and an 80% harvest recovery rate (combined efficiency = 0.8 × 0.8 = 0.64), then, at a typical density of 5 × 10⁴ in a 100 mm plate, the theoretical number of cells that can be recovered is approximately 3,926,990 × 0.64, or 2.51 × 10⁶.

• Cell lines vary significantly: larger, more spreading cells occupy fewer cells per area; smaller, more rapidly proliferating cells can achieve higher densities.

• The harvesting method affects recovery rates: trypsin/non-destructive cell collection methods (e.g., EDTA) and physical scraping yield different recovery rates. Enzymatic methods generally yield more complete cell recovery, but careful timing is required to avoid cell damage.