Extraction and identification of yeast KERNs.

. Objective To understandnucleic acids and to master the method of identifying nucleic acids. , principle,yeast
RNA content is more,
dna
less than 2%. RNA is soluble in alkaline solutions, and when alkalis are neutralization, ethanol is added to allow the dissummerated RNA to precipitate, resulting in RNA crude products. , equipment1. Dry yeast powder
2.
balance is . 3. Beech
4. Filter bottle
5. Breiton Funnel
6. Pipe tube
7. Glass bar
8. pH
test paper 9.
centrifuges . Fourth,
reagents1. 0.2% NaOH solution
2. Acetic acid (A.R
3. 95% ethanol
4. A waterless ether (C.P
5. Ammonia (C.P)
6. 10% H2SO4 solution
7. 5% AgNO3 solution:
5g AgNO3 dissolved in distilled water, fixed to l00ml, stored in brown bottles.
8. Moss black phenol a triclosan iron reagent
9. Fixed phosphorus reagent , operation1. The extraction of RNA
called taking 4g of dried yeast powder in a 100ml beo bowl, adding 0.2% NaOH solution to 40ml,
heating
30min in a boiling water bath and stirring frequently. Add a few drops of acetic acid to make the extract acidic. 4000r/min centrifugation 10 to 15min, take the night, stir while adding 95% ethanol washing twice, waterless ether wash twice, the precipitation transferred to the Cloth funnel filtration,
driding
after the coarse RNA.
2. Identification:
the above crude RNA 0.5g, plus 10% H2SO4 solution 5 ml, heated to boil 1 to 2min, to obtain RNA hydrolyte.
(1) alkaloids:
2 ml of hydrolytic solution, 2 ml of ammonia, 5% NaOH solution, to observe whether the production of floc-like pyridoline silver compounds.
(2) nuclear sugar:
0.5 ml hydrolyte, with moss black phenol-FeCI3; reagent 1 ml, heated to boil 1min, to observe color changes.
(3) phosphoric acid:
1 ml of hydrolytic solution, add 1 ml of phosphorus reagent, heating on the water bath, to observe whether the solution turned blue..