Why proper storage of stool for dysbacteriosis is critical for the accuracy of the analysis
Analysis of stool for dysbacteriosis - this is not just a formality, but a key diagnostic tool that helps to identify disorders of the intestinal microflora. The reliability of the results directly depends on how you collect data. Laboratories often refuse to accept samples if they were stored incorrectly, and doctors may order a repeat test - and this is not only a waste of time, but also additional costs. storing biomaterial, the reliability of the results directly depends. Laboratories often refuse to accept samples if they have been stored incorrectly, and doctors may order a repeat test—not only a waste of time, but also additional expense.
Unlike other tests (for example, blood or urine), stool contains living microorganisms that continue to multiply or die under inappropriate conditions. Even a few extra hours at room temperature can distort the real picture: some bacteria will multiply, others will die, and pathogenic microbes (for example Clostridium difficilemay become undetectable. Therefore, the question “how long can feces be stored for dysbacteriosis in the refrigerator” is not a quibble, but a guarantee that the treatment will be prescribed correctly.
In this article we will look at:
- ⏳ Maximum shelf life in the refrigerator and at room temperature
- 🧊 Optimal temperature and zones refrigerator for storage
- 🚫 Frequent errorsthat spoil the analysis (and how to avoid them)
- 📦 Requirements for containers and tightness
- 🩺 What to do if you don’t have time to get tested on time
Official standards: how long can feces be stored for dysbacteriosis in the refrigerator
According to the clinical recommendations of most laboratories (including Invitro, Helix, Hemotest), maximum shelf life of stool for dysbacteriosis in the refrigerator - 6-8 hours at temperature +2…+8°C. This is due to the fact that with a longer storage:
- 🦠 Quantity bifidobacteria and lactobacillus can decrease by 20–30%
- 🔬 Pathogenic microbes (for example, Staphylococcus aureus) can multiply to false positive values
- 🧪 The enzymatic activity of intestinal bacteria changes, which distorts the results of microflora imbalance
Important: some laboratories reduce this period to 4–5 hoursif the analysis includes a search opportunistic enterobacteria (for example, Klebsiella or ProteusCheck the requirements specific laboratory —they may differ!
⚠️ Attention: If you take the test in a public clinic, storage times may be stricter - up to 3–4 hoursThis is due to the peculiarities of transportation and processing of samples in budgetary institutions.
| Type of analysis | Max. shelf life in the refrigerator | Storage temperature | Notes |
|---|---|---|---|
| Dysbacteriosis (standard) | 6–8 hours | +2…+8°C | No freezing! |
| Dysbacteriosis + search for pathogens (Salmonella, Shigella) | 4–5 hours | +2…+6°C | Requires urgent delivery |
| Coprogram (general analysis stool) | 10–12 hours | +2…+8°C | Less sensitive to time |
| Carbohydrate analysis | 2–3 hours | +2…+4°C | Temperature sensitive |
If you do not have time to deliver the analysis to the laboratory within the specified time frame, it is better postpone collecting the material the next day. A repeat analysis will be cheaper than treatment for an incorrect diagnosis.
Where to store the container with the analysis in the refrigerator: choosing the right one zone
Not all sections of the refrigerator are equally suitable for storing feces. The main rule: avoid areas with temperature changes (for example, doors or top shelves next to the freezer). Optimal places:
- 🥬 Middle shelf - here the temperature is stable and is
+4…+6°C - 🥛 Zone for vegetables (if the temperature is not lower
+2°C) - suitable for short-term storage (up to 4 hours) - 🧊 Bottom shelf above the vegetable drawer - the coldest place, but do not allow freezing!
It is strictly forbidden to store the analysis:
- ❄️ In the freezer - freezing kills up to 90% of microorganisms when doing the analysis useless
- 🚪 On the door - the temperature here ranges from
+8°Cto+15°Cwhen opening - 🍖 Near raw meat or fish - risk of cross contamination
Before placing the container, wrap it in a paper towel - this will protect against condensation that can form due to temperature changes. Also make sure that the container. stands flatly, without tilting to avoid leakage.
Which container to choose: requirements for tightness and materials
Not every container is suitable for collecting and storing feces for dysbacteriosis. The best option is sterile plastic container with a spoon-spatula, which is given out in a laboratory or sold in a pharmacy. Why is this important:
- 🧴 Material: must be chemically neutral (polypropylene or polystyrene). data-i="142">Material
- 🔒 Tightness: the lid must close tightly to avoid oxidation of the sample with oxygen.
- 🧪 Volume: 5-10 g of feces is enough (about 1-2 teaspoons) There is no need to take more - this will not increase the accuracy.
What not to do:
- 📦 Use household containers (for example, yogurt containers) - they are unsterile and may contain residues of detergents.
- 🧻 Store stool in gauze or paper - this violates sterility and dries out the sample.
- 💊 Add to the container preservatives (for example, glycerin) without instructions laboratories - this will distort the results.
⚠️ Attention: If you buy a container at a pharmacy, check the label “For microbiological studies” on the packaging. Containers for general stool analysis (coprograms) may not be suitable for dysbacteriosis!
After collection. material:
- Close the container tightly.
- Sign it (last name, date and time of collection).
- Place in a sealed bag (for example, zip-lock) - this will protect against foreign odors in the refrigerator.
Buy a sterile container at the pharmacy
Sign the name and date of collection
Close the lid until it clicks
Place in a zip-lock bag
Place on the middle shelf refrigerator-->
What to do if you do not have time to take the test on time: emergency measures
Sometimes circumstances are such that it is not possible to deliver the test to the laboratory within the specified time frame. In this case, you can try the following options:
1. Use a preservative (only by agreement with the laboratory!)
Some laboratories allow special preservatives to be added to the container (for example, glycerin solution or saline solution), which slow down the growth of bacteria. However, this must be agreed upon in advance - independent addition of substances will distort the results.
2. Store in a thermal bag with ice
If transportation takes more than 2 hours, you can use a thermal bag with refrigerants (ice batteries). It is important that the temperature inside the bag remains within +2…+8°C. In this case, the total storage period (including time in the refrigerator) should not exceed 10–12 hours.
3. Postpone collection to the next day
If the delay is more than 8 hours, it is better do not risk to collect a new sample in the morning. This is especially important if the analysis is prescribed to diagnose serious diseases (for example, ulcerative colitis or dysbiosis after antibiotics).
⚠️ Attention: Some laboratories (for example, CITILAB) offer the service of "express delivery" of the analysis by courier. Specify this option when making an appointment - this can save the situation if you do not have time to deliver the sample yourself.
What happens if you submit an overdue analysis?
The laboratory may accept the sample, but the results will not be available. unreliable:
- False positive result for staphylococci or klebsiella (due to their reproduction).
- False negative result for bifidobacteria (due to their death).
- Incorrect data for lactose-negative enterobacteria, which will complicate the diagnosis of dysbacteriosis.
The doctor may prescribe a repeat test or incorrect treatment, which will lead to a deterioration of the intestinal condition.
Frequent errors when storing feces for dysbacteriosis: what spoils the analysis
Even if you comply with storage periods, some actions can make the analysis unusable. Here are the most common mistakes:
1. Storage at room temperature
Many people mistakenly believe that “a couple of hours on the table is not a big deal.” increase by 2-3 times within 2 hours, and +20°C quantity Escherichia coli can increase 2-3 times in just 2 hours, and enterococci begin to actively multiply. This leads to a false diagnosis of “excess bacterial growth.”
2. tools
Collecting stool a wooden stick or a spoon from the kitchen contaminates the sample with foreign bacteria. Use only a plastic spoon from a pharmacy container.
3. Freezing or overheating
Freezing kills up to 70% of anaerobic bacteria (for example, Bacteroides), and heating is higher +10°C accelerates the reproduction of pathogens. Even if the container is “a little frozen” on the back wall of the refrigerator, the analysis will have to be retaken.
4. Long-term storage in transport
If you are taking the test to the laboratory in the summer, do not leave it in the car - the temperature in the car can rise to +30…+40°C in 10–15 minutes. Use. thermal bag!
5. Failure to comply with collection rules
The analysis will be unreliable if:
- 🚽 Feces were collected after an enema or taking a laxative (distorts the microflora).
- 💊 You took less antibiotics than 2 weeks before collection.
- 🩸 The sample contains blood or mucus (you need to tell your doctor!).
How to prepare for analysis: rules for collecting stool for maximum accuracy
The accuracy of the analysis for dysbiosis depends 50% on the correct collection of material. Here are step-by-step instructions:
1. Preparation 3 days before collection
- 🍖 diet fatty foods, alcohol, spicy foods —they change the microflora.
- 💊 Cancel (by agreement with your doctor) probiotics, prebiotics, enzymes (for example, Linex, Hilak Forte).
- 🚫 Do not use rectal suppositories or ointments.
2. Collection of material
- 🚽 Use a clean, dry container (pot, vessel). Do not take feces from the toilet - detergents remain there!
- 🧴 Take feces from different parts (top, inside, sides) - this increases accuracy. 3–4 fragments feces from different parts (top, inside, sides) - this increases accuracy.
- 🕒 The optimal collection time is morningimmediately after waking up.
3. data-i="253">⏱️ Deliver the test to the laboratory
- ⏱️ Deliver the analysis to the laboratory within 2-3 hours (or store in the refrigerator for no more than 6 hours).
- 🚗 If you are traveling by car, put the container in thermal bag or wrap it in a cloth.
If you have liquid. chaircollect it in a container with a spoon, avoiding urine. For infants, collection from a diaper (but not from a diaper!) is allowed.
FAQ: Answers to frequently asked questions about storing stool for dysbacteriosis
Is it possible to store stool for dysbiosis in the freezer?
No, freezing is strictly prohibitedat temperatures below 0°C most anaerobic bacteria die (for example, Bifidobacterium), and the structure of the DNA of microbes changes, which makes the analysis uninformative. If you accidentally froze the sample, you will have to retake it.
What to do if feces are collected in the evening, and the laboratory works only in the morning?
In this case:
- Place the container in the refrigerator on middle shelf (
+4…+6°C). - Make sure that no more than 6–8 will pass from the moment of collection to delivery hours.
- If the delay is more than 8 hours, it is better to collect a new sample in the morning.
Can a yogurt container be used to collect stool?
No non-sterile household containers and may contain food or detergent residues that will skew the results. In addition, the plastic of food containers is often permeable. for oxygen, which accelerates the death of anaerobic bacteria. Use only pharmacy sterile containers.
How does taking antibiotics affect stool analysis?
Antibiotics suppress the growth of both pathogenic, as well as beneficial bacteria, so it is recommended to take a test for dysbacteriosis no earlier than 2 weeks after completing the course. If you need to take the test earlier (for example, to monitor treatment), warn your doctor - he will take this factor into account when interpreting the results.
Is it possible to store feces in the refrigerator next to products?
Technically possible, but it is better to place the container in a sealed bag (for example, zip-lock) or a plastic tray to avoid:
- The entry of foreign odors into the products.
- Risk of contact with food (for example, if the container leaks).
- Psychological discomfort for household members.
It is optimal to store the analysis on separate shelf, away from food.