Agarose gel electrophoresis - why does my bp not add up?
Will be as brief as I can! - any help would be appreciated. used 3 lanes on my gel and ran in each: lane 1: hyperladder (linear fragments) lane 2: EcoR1 digested recombinant pUC18 (size of insert unknown) lane 3: undigested recombinant pUC18 plasmid Results obtained from gel and standard curve: lane 2: 2 bands app ...continues
Presence of different species of Listeria in ready-to-eat food stuffs.
In product testing for Listeria in the Ready-to-eat food industry, is some Listeria safe for human consumption? How relevent is the question, if a ready-to-eat product contains cheese?
Bacteriology - Saccharomyces cerevisiae and Lactobacillus acidophilus
For the following two bacterial species: Saccharomyces cerevisiae and Lactobacillus acidophilus 1. What their basic cell shape (rod, spheres, etc)? 2. What type of cell envelope they have (gram negative, gram positive, or others)?
How does deep-freezing and freeze-drying preserve microorganisms?
How does deep-freezing and freeze-drying preserve microorganisms? How are microorganisms preserved?
Symbiotic nitrogen fixation by Rhizobium
As part of a practical we had to grow Rhizobium inoculated white clover seedlings in nitrate free agar and inoculated seedlings in nitrate free and nitrate supplemented medium. After several weeks of growth we had to determine the wet weight of the arial parts of each plant. We used the mean weights for the inoculated nitrate fr ...continues
How can you examine the plant species specificity of Rhizobium spp?
All I can think of is inoculating lots of different types of plant seedlings with the bacteria and comparing their growth with uninoculated seedlings. As the specificity of Rhizobia-plant interactions is dependant upon genes is there some molecular or genomic way of analysing this? any help at all would be appreciated - ...continues
Calculating Bacterial Numbers in Culture
Starting with 4 bacterial cells per milliliter in a rich nutrient medium, with a 1 hour lag phase and a 20 minute generation time, how many cells will there be in 1 liter of this culture after 1 hour? After 2 hours?
Determine the GC ratio of the following stretch of DNA from 2 different bacteria
Need some clarification please help. Determine the GC ratio of the following stretch of DNA from 2 different bacteria: Bacterium #1: GCATTAGCCGTATCCGAT CGTAATCGGCATAGGCTA Bacterium #2: CGACCGGCCATGGCGCGT GCTGGCCGGTACCGCGCA What conclusion would you draw about the relatedness of these 2 organisms and why?
Transposable elements cause mutations when the element is inserted within genes.
Transposable elements cause mutations when the element is inserted within genes. These elements disrupt the continuity of a gene and could render it useless. In light of this, explain how and why transposons can be useful to prokaryotes. Provide a specific example of how a transposon could be useful to a prokaryote.
The promoters for mRNA encoding early proteins in viruses like T4 have a different sequence
The promoters for mRNA encoding early proteins in viruses like T4 have a different sequence than the promoters for mRNA encoding late proteins in the same virus. Explain the viral strategy behind this and how promoter modification occurs.
