Extraction and identification of hepatic glycogen.

. First, the experimental purpose is1. To understand the nature of hepatic glycogen and master its extraction method.
2. Be familiar with the identification method of hepatic glycogen.
, experimental principle
glycogen belongs to polymer sugar
compound
, is the main storage form of sugar in animals, in the liver reserves are relatively rich. The synthesis and decomposition of glycogen in the body plays an important role in the regulation of blood sugar concentration.
glycogen is slightly soluble in water, non-reductive, and produces red with iodine. The common method of extracting hepatic glycogen is to grind fresh liver
tissue
with quartz sand to destroy liver tissue, add
proteins
from the solution of triclosate, and centrifuge to remove precipitation. The liver sugar principle in the upper liquid is achieved by adding ethanol precipitation. The precipitated glycogen is dissolved in water, partially added to iodine to observe the color reaction, and the other part is hydrolyzed with acid water into glucose, which is tested with Benedict
, a
reagent.III, instruments, raw materials and reagentsinstrument
research,
centrifuges
centrifuges, centrifuges, electric furnaces, a wide range of
test paper
, filter paper,
test tube
and so on.
raw
fresh animal liver
reagents
1. 10% of the solution of triclosan acetic acid
2. 5% of the solution of tetluco acetate
3.95% ethanol
4. Strong hydrochloric acid
5. 20% of the NaOH solution
6. iodine: iodine 1g, potassium iodide 2g dissolved in 500mL distilled water.
7. Platts reagents dissolved copper sulfate 17.3g in 100mL warm distilled water, sodium citrate 173g and aqueous sodium carbonate 100g in
700mL warm distilled water, cooled, stirred copper sulfate solution slowly into a mixture of citric acid and sodium carbonate, and finally diluted to 1000mL with distilled water. 4. Operation step
(i) extraction of hepatic glycogen
said to take about 1g fresh animal liver into the research, add a little quartz sand and 1mL10% of the triclosan acetic acid solution, grinding to the molybence and then add 2mL5% of the triclosan acetic acid continued to grind for a moment, so that into a uniform slurry, transferred to the centrifugal tube, 2500r/min centrifugation 10min. Take the liquid in another centrifuge tube, add 95% ethanol of the same volume, mix and leave for a moment, so that the glycogen is floc-like predisulate, and then put into the centrifuge 2500r/min centrifuge 10min. Discard the liquid and place the centrifugal tube upside down on the filter paper.
(ii) identification of hepatic glycogen
add 1mL distilled water to the liver glycogen precipitation, stir with a fine glass rod to dissolve, get glycogen solution.
1. Take 2 small test tubes, one add 10 drops of glycogen solution, the other add 10 drops of distilled water, and then two tubes add 2 drops of iodine, mix well. Observe the color changes in the tube and explain the phenomenon.
2. Add 3 drops of thick hydrochloric acid to the remaining glycogen solution, put them in a boiling water bath
heat
10min, remove the cooling, neutralized to neutral with 20% NaOH solution (pH test paper test). Add the plaque reagent 2mL, heat 5min in a boiling water bath and remove to cool. Observe the generation of precipitation in the tube and explain the phenomenon. .