Table 2 Comparison of storage methods, and factors important to the selection of the appropriate method
Storage method | Suitability for short-term field storage | Suitability for long-term field storage | Cost | Operational concerns | Additional requirements | Conclusions |
|---|---|---|---|---|---|---|
Filter paper | Excellent | Excellent | Comparatively expensive: ~$500 per pack of 100 | Cards holding DNA specimens require careful handling to protect from contamination during storage and transport. | Supply of sterile instruments or ability to sterilize instruments used to macerate insect abdomen onto card. | Effective for short- and long-term specimen storage. Substantial cost is a disadvantage. |
EtOH | Excellent | Suitable | Negligible: < $5 per liter | Airline restrictions on ethanol in baggage, and transporting ethanol internationally. | Tubes, or other containers to individualize blood meal specimens. | Effective for short-term storage, and inexpensive, but potential transportation issues. |
-20 °C | Poor | Poor | Negligible | Continued preservation required during transit. Availability of equipment. | Access to electricity for freezers, or supply of dry ice or liquid nitrogen. | Cold storage at -20 °C should be avoided, even when field conditions permit its use. |
Silica | Poor | Poor | Negligible | Airtight containers needed to protect silica from moisture absorption. | Tubes, or other containers to individualize blood meal specimens. | Preservation of blood meal specimens is ineffective. The method should be avoided. |