This post continues the “spices and salts” adventure that my roommate and I (both Bio 60 students this year) embarked on in our Foldscope explorations. For this exploration, I am writing about the dill and parsley samples we collected from the Spice Library at the Arrillaga Family Dining Commons. (As mentioned in our previous posts, anyone can visit the Spice Library and even bring some samples home in the Library’s provided small envelopes!)
Unlike the salt crystals from my previous post, the dill and parsley flakes were both viewed using wet mounts instead of dry mounts. Without water, the leaves appeared almost completely black under the microscope–making for an uninteresting (as well as uninformative) view. This is likely because the leaves were shriveled up in their dehydrated state, causing sections of the flakes to curl onto each other to create thick, opaque layers that easily blocked out light. Thus, wet mounts were needed to view these samples.
On the other hand, dry mounts were needed to view the salt crystals, as the crystals dissolve quickly in water. Thus, my two Microcosmos posts illustrate the importance of both wet and dry mounts, as well as knowing when to choose one over the other.
(Other notes on sample preparation: Wet mounts were held in place with tape on the glass slides, to help ensure that the sample did not move around while it was being viewed under the Foldscope. Realizing from previous Foldscope projects that it is quite easy to contaminate slides and cover slips with finger oils, I put on food preparation gloves that I had in my dorm room before preparing the samples.)
Without a microscope, it is already quite easy to distinguish dill from parsley: dill weed appears as thin, straight flakes while parsley flakes are broader and flat, appearing “leafier” than dill. These differences could be observed reasonably well under the microscope as well–the pieces of dill captured by the Foldscope-phone camera complex tended to have straighter edges than the parsley flakes.
Thanks for stopping by!
(Post is part of the #Bio60_2018 course.)