How Much Tissue and Silica Gel?
Collecting on silica is very straightforward. A 1 to 10 ratio of plant material to silica gel is commonly used. Thus, to dehydrate 1 g of tissue (wet weight), use 5 g of silica. Simply place the silica gel in a ziplock style plastic bag, add the plant tissue, and seal. Small (sandwich size) heavy gauge (freezer style) ziplock plastic bags are best because they do not tear. The material should be bone dry within 24 hours. If it is not, the silica gel may not have been fully dehydrated or the weight ratio was incorrect. I generally use grade 12 silica with a bit of indicator silica mixed in. The indicator silica “reports” when the silica is dehydrated (blue) or hydrated (pink). Some labs reuse silica gel (after baking it in an oven), but I worry about cross contamination, so I always use new silica. Labeling and Shipment. Label information is important, so please provide the following: • Taxon name • Collection number • Date of Collection • Specific Locality (latitude and longitude encou
