Saliva DNA Collection Cards: A Capable Assistant for Genetic Testing

Characteristics

(I) Convenient Collection

1. Non-invasive Collection

• One of the greatest advantages of saliva DNA collection cards is their non-invasive collection method. Compared with traditional blood collection, collecting saliva samples does not require needle puncture of the skin, avoiding risks such as pain, infection, and fainting due to blood drawing. It is especially suitable for those who are afraid of blood collection, such as children, the elderly, and patients with blood diseases. Users only need to put the collection card into their mouths, let saliva moisten the collection area, or follow the instructions in the manual, rinse their mouths simply and then spit saliva onto the collection card. The whole process is simple, quick, and painless, greatly improving the compliance of sample collection.

2. Easy to Operate

• The operation method is very simple and easy to understand, and does not require the assistance of professional medical staff. Even ordinary people without a medical background can easily complete the collection of saliva samples according to the detailed instructions. Generally, there will be clear markings and instructions on the collection card, telling users how to correctly collect saliva, the amount of collection, and precautions. For example, some collection cards are designed with a collection area of a special shape. Users only need to place the collection area under the tongue or on the inside of the cheek, gently chew or roll the tongue to make the saliva fully moisten the collection area, and then take out the collection card to dry it or handle it according to a specific storage method. The whole process usually only takes a few minutes and is very convenient and quick.

(II) Stable Storage

1. Long-term Storage

• Saliva DNA collection cards adopt special materials and designs to ensure that the collected DNA remains stable for a long time. Generally, under appropriate storage conditions (such as a dry and low-temperature environment), the DNA in the samples can be preserved for several years or even decades. This is very important for some projects that need to store samples for a long time for subsequent research or repeated testing. For example, in some large genetic disease research projects, researchers may collect a large number of saliva samples and store them in a specialized sample bank. Using saliva DNA collection cards can ensure that the DNA in these samples still has sufficient quality and integrity after many years, so as to conduct further genetic analysis and research, providing long-term data support for the exploration of disease pathogenesis and treatment methods.

2. Strong Anti-contamination Ability

• The collection cards have good anti-contamination ability and can effectively prevent external factors from destroying and contaminating the sample DNA. Their surfaces are usually specially treated and have functions such as waterproofing, antibacterial, and anti-ultraviolet. During the collection, transportation, and storage processes, even if the samples come into contact with a certain amount of dust, bacteria, or other impurities, it is not easy to have a significant impact on the quality of the DNA. This enables saliva DNA collection cards to be used in relatively complex environments, such as when collecting samples in the wild or when samples need to be transported over long distances. They can still ensure the stability and reliability of the DNA and the accuracy of the test results.

(III) High Efficiency of DNA Extraction

1. High-quality DNA Extraction

• Saliva DNA collection cards can effectively collect and preserve the DNA in saliva, and in the subsequent extraction process, high-quality DNA can be obtained. This is because the material and structural design of the collection cards can maximize the adsorption of cells in saliva while avoiding cell rupture and DNA degradation. In the laboratory, by using specialized DNA extraction kits in combination with the collection cards, pure and complete DNA can be efficiently extracted to meet the requirements of various genetic testing techniques, such as PCR (polymerase chain reaction) and gene sequencing. For example, when conducting high-precision gene sequencing, a high-quality DNA template is required. The DNA extracted by saliva DNA collection cards can well meet this requirement, ensuring the accuracy and reliability of the sequencing results and providing strong support for disease diagnosis and genetic research.

2. High-yield DNA Extraction

• Compared with some other saliva DNA collection methods, saliva DNA collection cards usually can extract a larger amount of DNA. This is very advantageous for some experiments or testing projects that require a large amount of DNA for analysis. For example, in large-scale genetic studies such as genome-wide association analysis (GWAS), a large amount of DNA samples are needed for genotyping and statistical analysis. Using saliva DNA collection cards can extract a sufficient amount of DNA from a single sample collection, reducing the trouble of having to collect samples multiple times due to insufficient DNA amounts, improving research efficiency, and also reducing costs and error risks.

III. Precautions

(I) Preparation Before Collection

1. Avoid Eating and Drinking

• Before collecting saliva samples, it is generally recommended that users refrain from eating and drinking for at least 30 minutes to 1 hour. This is because eating and drinking may dilute the DNA concentration in saliva and affect the subsequent test results. For example, if a large amount of water is drunk just before collection, the number of cells in saliva will be relatively reduced, resulting in insufficient DNA extraction and possible inaccurate test results or failure to detect certain gene mutations. In addition, components in some foods and drinks, such as acidic substances and pigments, may cause chemical damage to DNA and reduce the quality of DNA. Therefore, these foods and drinks should be avoided before collection.

2. Clean the Mouth

• Before collection, rinse the mouth with clean water to remove food residues, bacteria and other impurities in the mouth. However, it is important to avoid brushing teeth too vigorously or using mouthwashes containing alcohol, antibiotics and other ingredients, because these operations may cause damage to the oral mucosa, causing cells to fall off into the saliva and increase the impurity content in the sample, affecting DNA extraction and testing. Generally, gently rinsing the mouth 1 – 2 times with clean water is sufficient to ensure the cleanliness of the mouth without adversely affecting the sample.

(II) Collection Process

1. Correct Collection of Saliva

• Users should collect saliva correctly according to the instructions on the collection card. Generally speaking, it is necessary to ensure that a sufficient amount of saliva is collected, usually 2 – 3 milliliters of saliva. During the collection process, avoid saliva splashing out of the collection card to prevent sample loss. If saliva is collected by chewing or rolling the tongue, pay attention to moderate strength to avoid damaging the oral mucosa. At the same time, ensure that the collection area of the collection card is fully moistened with saliva to ensure that enough cells and DNA can be collected. For example, some collection cards need to place the collection area under the tongue or on the inside of the cheek. Users should keep this position for a while to allow the saliva to fully penetrate into the collection material, and then take out the collection card for subsequent processing.

2. Avoid Sample Contamination

• During the collection process, pay attention to keeping the collection environment clean and avoid sample contamination by external factors. Users should avoid touching the collection area with their hands and try to use clean tweezers or other tools to operate the collection card. If accidentally in contact with other items, such as the desktop or hair, during the collection process, stop collecting immediately and replace with a new collection card to prevent the DNA or impurities in other substances from contaminating the sample and affecting the accuracy of the test results. In addition, the collection site should avoid the presence of strong light, high temperature or chemical substances and other factors that may damage DNA.

(III) Post-collection Treatment

1. Timely Drying and Storage

• After collecting saliva, the collection card should be dried as soon as possible or processed according to the requirements in the instructions. Generally, the collection card can be placed in a well-ventilated, dry place to dry naturally, or a specialized drying device can be used for drying. Avoid placing the collection card in a humid environment to prevent DNA degradation or the growth of bacteria and other microorganisms, which may affect the sample quality. The dried collection card should be stored in a dry, cool, and dark place, such as a specialized sample bag or sample box, and marked with information such as the collection date and the person who collected it for subsequent identification and management.

2. Follow the Temperature Requirements for Storage

• Different saliva DNA collection cards may have different temperature requirements for storage. Generally speaking, short-term storage at room temperature (usually not more than 1 – 2 weeks) is feasible, but for long-term storage, it is recommended to store the collection card in a low-temperature environment, such as a -20 °C or -80 °C refrigerator. During transportation, it is also necessary to ensure that the collection card is under appropriate temperature conditions. Ice packs or dry ice and other refrigeration equipment can be used to maintain a low-temperature environment to prevent DNA degradation caused by high temperature. For example, if the collection card needs to be transported over a long distance to a testing institution, it should be packaged in an insulated box containing sufficient ice packs and ensure that the ice packs remain in a low-temperature state during transportation to ensure the quality of the sample and the accuracy of the test results.

Saliva DNA collection cards, with their characteristics of convenient collection, stable storage, and high efficiency of DNA extraction, have been widely used in multiple fields such as medicine, forensic science, and anthropology, providing strong support for genetic testing and research. However, during the use process, it is necessary to strictly follow the precautions to ensure that the collected saliva samples can accurately reflect an individual’s DNA information, so as to give full play to their advantages in various fields and provide a reliable data basis for scientific research and practical applications.