What is the difference between Dextrose and Molasses media?
- Behavioral Studies: Use dextrose if your lab conducts olfactory or learning and memory assays. Molasses introduces strong, complex odors and chemical volatiles that can alter baseline sweet taste sensing or mask the experimental odors used during testing. [1, 2]
- Phenotypic Scoring and Imaging: Choose dextrose when you need to closely observe life stages. The pale background makes it much easier to count tiny embryos, separate virgin females, track larval foraging paths, or screen for subtle cuticle and eye color markers. [1, 2]
- Strict Dietary & Metabolic Restrictions: Opt for dextrose if you are mapping exact macronutrient intake. Because dextrose is a pure sugar, you can change its concentration without inadvertently altering trace mineral or micronutrient levels. [1, 2, 3]
- Preventing Bacterial Slime: Dextrose is highly effective at reducing the growth of specific contaminants likeLeuconostoc bacteria. It prevents these bacteria from synthesizing a thick, suffocating slime coat over the media surface.
- General Stock Maintenance: Use molasses for standard, long-term line propagation. Laboratories like the Bloomington Drosophila Stock Center traditionally use cornmeal-molasses-yeast recipes because they provide a highly reliable, robust baseline environment. [1, 2, 3]
- Sick, Low-Yield, or Sensitive Lines: Switch to molasses if a particular genetic strain is dying out or underproducing. The trace minerals and complex nutrients naturally present in unrefined molasses offer a metabolic boost that often increases overall fly fertility and egg-laying yields. [1, 2]
- Egg Collection Plates: Choose molasses when creating agar plates for large-scale embryo collection. The dark brown color creates a stark visual contrast against the pearly-white fly embryos, making automated or manual picking under a stereomicroscope incredibly efficient. [1, 2]
- Preventing Food Desiccation: Select molasses if you face dry incubator conditions. Because molasses retains moisture better than dextrose, it stops the media from pulling away from the vial walls too quickly, protecting wandering larvae from drying out.
Cotton, flugs or Press-n-Seal?
We provide three options for vial closures to our customers: cotton balls, flugs, or Press-n-Seal. The cotton balls are of pharmaceutical grade and machine processed for consistent uniformity. Flugs are made of bonded dense weave cellulose and are said to provide a better barrier to mites than cotton and rayon, and offer minimal shedding compared to cotton and rayon as well as reduced evaporation, which keeps food fresh longer. Glad Press’n Seal plastic wrap is applied as a sheet over each tray of vials, removing the need to unplug each individual vial. The seal has been found to significantly increase the shelf life of prepared fly food.
I didn't get my order when I expected it.
Orders are made and delivered on a weekly basis. Orders submitted by Sunday will be made and delivered by the following Friday. If you did not receive your order, please contact our media lead, wjadams@stanford.edu