Okavango Delta Expedition

 
June 21, 2000
Plant Press – Fred Ellery of the Plant Team
prepares his samples.

Preparing a Specimen

The scientists have spent long days collecting a variety of specimens. While they are all experts, it's impossible to identify every species right off the bat.

Now, as the expedition is drawing to a close, the scientists will return to their respective institutions and begin the process of identifying their samples. But first, they must get the specimens home in one piece. Here are some of the ways the scientists preserve their specimens for the journey.

Plant Press

In field conditions, it takes approximately two weeks to dry a specimen before it can be mounted and placed in a herbarium for future reference. Papers should be changed every few days to encourage drying. Of course it isn't available in the field, but a drying oven, which heat to 60 degrees Celsius, can also be used to speed up the drying process.

Formalin and Propanol

Zooplankton and fish must be immediately placed in formalin, a preservative that prevents proteins and pigmentation from changing. This chemical allows scientist to test DNA and identify specimens at a later stage. Fish need an additional step for proper long-term storage: propanol is used after the sample has been fixed in formalin for approximately 10-14 days.

Invertebrates Samples Preserved
in Ethanol

 

Ethanol

Invertebrate species are preserved in ethanol, a form of alcohol.

Labeling/Storage

Specimens are placed in bottles, jars or vials, then labeled using waterproof ink. Each specimen is given a collection number, which will be added to a database for future reference.

– Reported by Sharon Safran

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