How to Use Sample Storage Vials Correctly to Extend Sample Lifespan

**Author: Original from Internet

In the laboratory, sample preservation is a crucial part of the experimental process. Correct sample preservation methods can effectively extend the lifespan of samples and ensure the accuracy and reliability of experimental results. As sample storage vials are the primary tools for sample preservation, their correct usage and the precautions to be taken are of paramount importance. The following is a detailed guide on how to use them correctly to extend sample lifespan.

Selecting the appropriate sample storage vials is the first step in ensuring effective sample preservation. Different sample properties and experimental requirements dictate varying specifications regarding the material, capacity and shape of the storage vials.

The material of the sample storage vials directly affects the stability of the samples. Common materials for storage vials include glass, polypropylene (PP), and polytetrafluoroethylene (PTFE). Glass vials offer good chemical stability and are suitable for storing most chemical reagents and biological samples, but they are fragile and relatively heavy. Polypropylene vials are highly corrosion-resistant, making them suitable for storing acidic and alkaline solutions as well as organic solvents, and they are relatively inexpensive. Polytetrafluoroethylene (PTFE) vials, on the other hand, possess extremely high chemical inertness and heat resistance, making them suitable for storing high-purity samples and highly corrosive reagents, though they are more expensive.

The capacity should be selected based on the sample volume and experimental requirements. A bottle that is too large may result in the sample occupying too little space within the bottle, making it prone to volatilization or deterioration due to contact with air; conversely, a bottle that is too small may be unable to accommodate a sufficient sample volume, thereby affecting experimental procedures. Generally, the sample volume should occupy 70%–80% of the bottle’s capacity, ensuring that the sample has sufficient space while minimizing contact with air.

The shape of the storage bottle also affects the effectiveness of sample preservation. Round-bodied bottles have a relatively small surface area, which reduces the contact area between the sample and the air, making them suitable for storing volatile or easily oxidised samples. Furthermore, bottles with ground-glass stoppers or screw caps provide a better seal, effectively preventing sample leakage or the ingress of external contaminants.

The following points should be noted when filling samples:

Samples should not exceed 80 per cent of the bottle’s capacity to prevent spillage during storage due to temperature changes or liquid expansion. Furthermore, leaving some space allows for the sample to mix evenly.

Before filling the sample, ensure that the storage vial and cap are clean. They may be washed with deionised water or a specialised cleaning agent prior to use, and dried with a clean cloth or tissue. If the sample is sensitive to moisture, ensure the vial is completely dry before filling it.

When filling with liquid samples, pour slowly to avoid creating air bubbles. Air bubbles may cause the sample to separate into layers or affect its homogeneity; particularly when storing samples prone to oxidation, air bubbles increase the surface area of the sample in contact with air, accelerating its deterioration.

Sealing is a crucial step in ensuring effective sample preservation. Choosing an appropriate sealing method can effectively prevent sample leakage, volatilisation or contamination from external sources.

Select an appropriate sealing method based on the nature of the sample and storage requirements. For general chemical reagents and biological samples, ground-glass stoppers or screw caps may be used. For high-purity or volatile samples, screw caps with sealing gaskets or Teflon lids may be used to enhance the seal. For samples requiring long-term storage, vacuum packaging or inert gas protection may also be employed.

Clearly labelling sample information on storage vials is key to ensuring sample traceability and experimental accuracy. Labelling should include details such as the sample name, concentration, preparation date, expiry date and the person who prepared the sample. Waterproof, corrosion-resistant markers or labels should be used, and labels must be securely affixed to the surface of the vial to prevent loss of sample information due to the label falling off.

Storage conditions have a crucial impact on sample stability. Different samples require different storage environments; therefore, when using sample storage vials, appropriate storage conditions should be selected based on the nature of the sample.

Temperature is one of the primary factors affecting sample stability. Temperature-sensitive samples, such as bioactive substances and enzymes, should be stored in a low-temperature environment, such as a 4°C refrigerator or a -20°C freezer. General chemical reagents may be stored at room temperature, but direct exposure to high temperatures should be avoided to prevent decomposition or volatilisation.

Humidity also has a significant impact on sample preservation. Samples prone to moisture absorption, such as anhydrous reagents and desiccants, should be stored in a dry environment; desiccators or dehumidifiers may be used. For biological samples that require a specific level of humidity, an appropriate amount of humectant, such as distilled water or glycerol, may be added to the storage vial.

Exposure to light may cause certain samples to undergo photochemical reactions, affecting their stability. Light-sensitive samples, such as certain organic reagents and biological samples, should be stored in a light-protected environment; brown bottles may be used, or the samples may be placed in light-shielding containers.

Regularly checking the condition of sample storage bottles is a crucial step in ensuring sample safety. Regular inspections enable the timely detection of issues such as sample deterioration or leakage, allowing appropriate measures to be taken.

Regularly inspect the bodies and caps of storage vials for damage, cracks or signs of ageing. If any damage is detected, the vials should be replaced immediately to prevent sample leakage or contamination.

Regularly observe changes in the colour, state and odour of samples to detect signs of deterioration in a timely manner. Should any abnormal changes in the sample be detected, the cause should be analysed promptly and appropriate measures taken, such as re-preparing the sample or adjusting the storage conditions.

Regularly maintain the storage environment to ensure that conditions such as temperature, humidity and light exposure in the storage area meet the required standards. For storage equipment such as refrigerators and freezers, defrosting, cleaning and temperature calibration should be carried out regularly to ensure their proper operation.

The correct use of sample storage vials is key to extending the shelf life of samples and ensuring the accuracy and reliability of experimental results. When using sample storage vials, one should select the appropriate material, capacity, and shape based on the nature of the sample and experimental requirements; fill the vials correctly, seal them, and label them; and, in accordance with the sample’s requirements, choose suitable storage conditions while regularly inspecting and maintaining both the vials and the storage environment. Through these measures, the shelf life of samples can be effectively extended, ensuring the smooth progress of experiments and the accuracy of results.