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United States Biological

Everything for your Yeast Lab:
   This is a great time to stock up on basic supplies for your yeast lab. On top of our already low prices, we are offering a 10% discount on Zymolyase, 5-FOA, and Yeast Mating Factor. USBiological also manufactures a broad selection of yeast growth media for Saccharomyces cerevisiae, Schizosaccharomyces pombe, and Picha pastoris, including Drop-Out Media, YPD Media, and Edinburgh Minimal Media. Proprietary blending technology ensures homogeneity, and blended media are subject to complete growth analysis. You can choose one of our standard mixes or have a medium customized to your specific requirements.

Feature:Drosophila Egg

Zymolyase, 5-FOA,
and Yeast Mating Factor

  Zymolyase, produced by a submerged culture of Arthrobacter luteus, is an essential enzyme responsible for lysis of viable yeast cell walls. This lytic activity releases spheroplasts and protoplasts in the preparation of yeast DNA prior to restriction enzyme digestion and Southern Blot analysis .The extent of lysis of yeast cells by Zymolyase varies with yeast strain, growth stage of yeast and cultural condition.

(promo code 041509)

Drosophila Diet Medium K12

Medium is a new insect food particularly indicated for Drosophila melanogaster flies' growth and propagation. Our medium has advantages over existing rich traditional media (containing molasses or corn):
Hatching Time

-Greatly improves (about 100%) the overall hatching rate (18-20 hours). Flies raised on K12 Medium hatch over a 4-5 day period instead of the 2-3 days of traditional media, greatly facilitating the collection of virgins and the use of young adults for healthy crosses (Fig.1).

-Yields about 200% more larvae and adult flies. This is particularly relevant for the propagation of precious mutant Drosophila strains, which are less viable and used as models for studying human genetic diseases.

-Increases the levels of egg deposition (18-20 hours) by about 50%.

(promo code 040109)

Yeast Growth Media
Selecting the Right One

  There are a wide variety of yeast media formulations available. The choice should be made based on the type and strain of yeast, the type of desired growth, and of course the details of the work being done. Agar can be added to media for a solid growth substrate.

  Yeast Nitrogen Base (YNB) formulations are a blend of YNB and a carbon source such as dextrose, galactose, or raffinose. To make the desired synthetic defined medium, ammonium sulfate and selected amino acids and nucleosides are added. These are often called drop-out media because depending on the auxotroph being studied, one or more components is "dropped out". These media are useful for confirming a strain's phenotype, selecting yeast transformants, and culturing the organism.

  YPD medium is composed of peptone, dextrose, and yeast extract. As it is an undefined, complete medium, it is not suitable for studying auxotrophs but can be used for growing most Saccharomyces cerevisiae strains. YPDA is the same formulation as YPD, but supplemented with adenine hemisulfate supplement. The adenine is added to provide faster growth, higher saturation densities, and the absence of red/pink color in ade1 and ade2 mutants. YEP medium is YPD without the dextrose, so the carbon source can be chosen by the user.

  Schizosaccharomyces pombe prefers slightly different conditions. YE Medium is made with yeast extract and dextrose. This medium inhibits sporulation and conjugation in S. pombe. YES is YE with amino acid and nucleoside supplements, for a complete S. pombe growth medium.

  Edinburgh Minimal  Medium is an S. pombe medium containing glucose, salts, vitamins, and minerals, also used for vegetative growth. With low glucose, it is used for yeast transformations. With minimal glutamate it is used for sporulating diploids.

Drop out media

Yeast Nitrogen Base (with or without AS, amino acids, other amendments)- Table 1

Drop out base (yeast nitrogen base + ammonium sulfate + carbohydrate)- Table 2

Drop out mix complete (without YNB, with all amino acids, with or without other amendments)- Table 3

Custom drop out mix (without YNB, without one or more amino acids or nucleosides of your choice)- Table 4



5-Fluoroorotic Acid
  Useful in the identification and selection of the strains of Saccharomyces cerevisiae that contain the mutant ura3- gene. 5-FOA is toxic to yeast cells that can synthesize the enzyme orotidine-5’-phosphate dicarboxylase (Ura+) and they are therefore unable to grow on 5-FOA-containing media.

Yeast Mating Factor
  is an inhibitor of DNA synthesis for alpha-type mating cells of S. cerevisiae. This synthetic peptide is the mating pheromone alpha factor. Alpha-factor pheromone arrests yeast in G1 of the cell cycle by inducing mating genes which alter the cell surface.

Yeast Extract
  Yeast Extract is produced from autolyzed yeast cells and is very soluble in water. It is used as an enrichment in a large number of culture media.