Diatoms genome sequencing You have an average number of diat

Diatoms genome sequencing You have an average number of diatoms/field of view at 400x We used 20 mu l of H_2O that contained an unknown number of diatoms The total area at 400x magnification was pi*25^2 = 1963.495 mu m^2 The average mass of a diatom is 0.00043 g Of the total mass, 0.06% is nuclear DNA, 0.008% is chloroplast DNA and 0.01% is mitochondrial DNA As a helpful tip...1963.495 mu m^2 = 0.9817 mu l How many diatoms are present in 1 mu l of H_2O? How much H_2O do you need to acquire 1.8 mu g of chloroplast DNA? How much H_2O do you need to acquire 20 mu g of nuclear DNA?

Solution

So what we know is that we have 4.6 diatoms in fiels of view (FOV). that is 4.6 diatoms per 0.9817micro liters of water.

So in 20micro liters we have 93.7148 diatoms

and therefore in 1 liter we get 4.686 X10⁶ diatoms.

Now the average mass of diatom is given as 0.00043g which is 430 micrograms, of which 0.06%is nuclear DNA (nDNA), 0.008% is Chloroplast DNA (cDNA) and 0.01% is mitochondrial DNA (mDNA).

that is of the 430 micrograms (1 diatom), nDNA weighs 0.258micrograms, cDNA weighs 0.0344micrograms,

So to get 1.8 micrograms of cDNA we need approximately (1.8/0.0344= 52.326 diatoms), we know that there are 4.6diatoms in 0.98 microliters of water, therefore we need to take 11.14microliters of water to get 1.8 micrograms of chloroplast DNA. and similarly to get 20 micrograms of nuclear DNA we need (20/0.258= 77.519 diatoms) that is 16.548 microliters of water.