Note the compactness of the chromosomes during cell division. They are twisted in a tight spiral and have the form of thick sticks. At this time, DNA is metabolically inert.

Date: 2015-10-07; view: 485.

The preparation of DNA is elective with the painting in green and RNA in red. Note the characteristic distribution of the cells. So it is possible to note the content of RNA in nucleoli and cytoplasm, the DNA is predominantly found in the nucleus.

Micropreparations

Convenient for the preparation of slices can serve as thymus, spleen, lymph nodes, and so the identification of DNA should be performed by the method Felgina. Freed from the paraffin sections were placed for the hydrolysis in 1N. HCl at 56 for 10-30 minutes then transferred to Schiff's reagent na40-80 minutes. After that, sections were transferred to a sulphite water. Sections were rinsed, dehydrated, and enclosed in balsam.
The preparation produced painting in red of a specific DNA. Consider a drug and make a preferential arrangement of DNA in cell nuclei.

Differential detection of DNA and RNA in tissue sections

Micropreparations
For the preparation of slices can be recommended to the fabric of the pancreas. Coloring is done with methyl green + pironin. The success of the color depends largely on the quality of the reagent.

DNA in the chromosomes at different nuclear states
State of the chromosomes in dividing cell
Micropreparations. Immersion (or slide)

Polytene chromosomes of salivary gland cells of larvae of Diptera