Laboratories should provide relevant personnel with correct instructions for specimen handling and transportation in accordance with national or regional regulations and molecular diagnostic test kit instructions. Each specimen should pay attention to the following points: collection time and date, date of transportation, date of receipt by the laboratory, and temperature at which the specimen was received. The transport conditions for different types of specimens are not necessarily the same.
1. Whole Blood, Serum, and Plasma Blood samples for DNA analysis can be stored at room temperature for 24 hours and stored at 2-8°C for 72 hours. Blood for RNA analysis should be collected in tubes containing RNA stabilizers. Whole blood is unstable and artificial gene induction and RNA degradation may occur. It is not recommended for gene transcription analysis. Serum for DNA or RNA studies is transported using dry ice. Plasma can be transported at 2-8°C and stored at -20°C.
2. Dry Blood Spot (DBS) DBS is suitable for DNA analysis but is not recommended for studies that require complete RNA. Once air-dried, the DBS should not be placed in a sealed bag. A moist environment will promote microbial growth. If placed in a plastic bag or other container, a sufficient amount of desiccant should be added to minimize the humidity in the container and a dry indicator or humidity card should be used to monitor whether the specimen is in an excessively humid environment. To avoid cross-contamination, multiple DBS specimens are separated by thin cellophane or placed in some way without touching each other. DBS can be transported at room temperature.
3. BAL BAL specimen transport and testing should be performed within 24 hours after collection. If not, place it in a freezer at 2-8°C for up to 72 hours, or freeze at -70°C for future testing. Specimens of M. tuberculosis should be washed and digested before cryopreservation or before long-term storage.
4. Bone marrow puncture (BMA) Bone marrow is punctured with a needle containing EDTA anticoagulant. The person responsible for specimen receipt and handling should be notified as soon as the specimen is served. Specimens for DNA extraction can be stored temporarily at 2-8°C. Bone marrow puncture specimens for RNA research should be placed in RNA stabilizing solution as soon as possible or immediately placed on ice cubes and sent to the laboratory. If the specimen is unstable and cannot be frozen, RNA extraction should be performed within 1-4 hours.
5. Oral Mucosal Cells Mouthwash is usually the source of oral mucosal cells. Use RNA Stabilizers to protect RNA in oral mucosal cells and rinse samples. Oral mucosal cells used for DNA studies can be collected with swabs and dried at room temperature for transport. DNA-based mouthwash specimens can also be shipped at room temperature and remain stable for a week.
6. Leukocyte Layer If the blood sample for DNA detection does not extract DNA within 3 days of blood collection, the leukocyte layer may be separated and stored at -70°C for DNA detection. The leukocyte layer used to detect EBV should be frozen and transported on dry ice. RNA should be isolated from the leukocyte layer within 1-4 hours after sample collection, or the cells should be stored in RNA stabilizer at room temperature.
7. Cerebrospinal Fluid (CSF) Cerebrospinal fluid used for DNA research should be transported at 2-8°C. If specimens cannot be processed immediately, CSF specimens used to detect DNA viruses should be placed below -20°C or -70°C. The CSF specimens should be immediately frozen and RNA extracted within 1-4 hours of collection. If not, red cells should be removed immediately after freezing and transported to the laboratory on dry ice.
8. Tissue Tissues used for DNA extraction should be immediately frozen and transported to the laboratory with ice, processed within 24 hours at 2-8°C, or frozen at the collection point. DNA is usually stable at 2-8°C for 24 hours, stored at -20°C for at least 2 weeks, and -70°C for at least 2 years. The tissue sample used for RNA extraction should be quickly frozen or stored below -70°C with the addition of stabilizers or RNA extraction within one hour after sample collection. Tissue samples frozen in liquid nitrogen were shipped using dry ice and stored at -70°C prior to RNA extraction. Frozen specimens cannot be thawed prior to RNA extraction and homogenized using guanidinium isothiocyanate buffer or other suitable extraction media. If you cannot quickly freeze or immediately stabilize, RNA should be isolated within 4 hours of collection (preferably 1 hour). The treated or purified RNA is preferably stored in ethanol at -70°C.
9. Sputum The sputum used for DNA analysis is collected in a sterile container and transported to the laboratory at room temperature. If it cannot be transported for more than 30 minutes, it should be refrigerated, or it should be transported at 4-8°C if the transport time exceeds 30 minutes.
1. Whole Blood, Serum, and Plasma Blood samples for DNA analysis can be stored at room temperature for 24 hours and stored at 2-8°C for 72 hours. Blood for RNA analysis should be collected in tubes containing RNA stabilizers. Whole blood is unstable and artificial gene induction and RNA degradation may occur. It is not recommended for gene transcription analysis. Serum for DNA or RNA studies is transported using dry ice. Plasma can be transported at 2-8°C and stored at -20°C.
2. Dry Blood Spot (DBS) DBS is suitable for DNA analysis but is not recommended for studies that require complete RNA. Once air-dried, the DBS should not be placed in a sealed bag. A moist environment will promote microbial growth. If placed in a plastic bag or other container, a sufficient amount of desiccant should be added to minimize the humidity in the container and a dry indicator or humidity card should be used to monitor whether the specimen is in an excessively humid environment. To avoid cross-contamination, multiple DBS specimens are separated by thin cellophane or placed in some way without touching each other. DBS can be transported at room temperature.
3. BAL BAL specimen transport and testing should be performed within 24 hours after collection. If not, place it in a freezer at 2-8°C for up to 72 hours, or freeze at -70°C for future testing. Specimens of M. tuberculosis should be washed and digested before cryopreservation or before long-term storage.
4. Bone marrow puncture (BMA) Bone marrow is punctured with a needle containing EDTA anticoagulant. The person responsible for specimen receipt and handling should be notified as soon as the specimen is served. Specimens for DNA extraction can be stored temporarily at 2-8°C. Bone marrow puncture specimens for RNA research should be placed in RNA stabilizing solution as soon as possible or immediately placed on ice cubes and sent to the laboratory. If the specimen is unstable and cannot be frozen, RNA extraction should be performed within 1-4 hours.
5. Oral Mucosal Cells Mouthwash is usually the source of oral mucosal cells. Use RNA Stabilizers to protect RNA in oral mucosal cells and rinse samples. Oral mucosal cells used for DNA studies can be collected with swabs and dried at room temperature for transport. DNA-based mouthwash specimens can also be shipped at room temperature and remain stable for a week.
6. Leukocyte Layer If the blood sample for DNA detection does not extract DNA within 3 days of blood collection, the leukocyte layer may be separated and stored at -70°C for DNA detection. The leukocyte layer used to detect EBV should be frozen and transported on dry ice. RNA should be isolated from the leukocyte layer within 1-4 hours after sample collection, or the cells should be stored in RNA stabilizer at room temperature.
7. Cerebrospinal Fluid (CSF) Cerebrospinal fluid used for DNA research should be transported at 2-8°C. If specimens cannot be processed immediately, CSF specimens used to detect DNA viruses should be placed below -20°C or -70°C. The CSF specimens should be immediately frozen and RNA extracted within 1-4 hours of collection. If not, red cells should be removed immediately after freezing and transported to the laboratory on dry ice.
8. Tissue Tissues used for DNA extraction should be immediately frozen and transported to the laboratory with ice, processed within 24 hours at 2-8°C, or frozen at the collection point. DNA is usually stable at 2-8°C for 24 hours, stored at -20°C for at least 2 weeks, and -70°C for at least 2 years. The tissue sample used for RNA extraction should be quickly frozen or stored below -70°C with the addition of stabilizers or RNA extraction within one hour after sample collection. Tissue samples frozen in liquid nitrogen were shipped using dry ice and stored at -70°C prior to RNA extraction. Frozen specimens cannot be thawed prior to RNA extraction and homogenized using guanidinium isothiocyanate buffer or other suitable extraction media. If you cannot quickly freeze or immediately stabilize, RNA should be isolated within 4 hours of collection (preferably 1 hour). The treated or purified RNA is preferably stored in ethanol at -70°C.
9. Sputum The sputum used for DNA analysis is collected in a sterile container and transported to the laboratory at room temperature. If it cannot be transported for more than 30 minutes, it should be refrigerated, or it should be transported at 4-8°C if the transport time exceeds 30 minutes.