Phaseolus polytene chromosomes

Fluorochrome banding

For fluorchrome banding with 4',6-Diamidin-2-phenyl-indol (DAPI) polytene chromosomes have been incubated for 10 min.

In order to get a differential fluorochrome banding of blue, pink and white preparations have been stained in a mixture of DAPI and propidiumiodid (DAPI/PI).
As material were used chromosome prerpations at least 24 hours after pretreatment or slides used previously for FISH.


  • prepare new staining solution and store protected form light
  • incubate chromosome preparations in 60 ml staining solution in a dark place at least overnight at room temperature
  • rinse slides in PBS and remove access of liquid
  • cover chromosome preparations in 10 µl of mounting medium and leave in the dark for at least 30 min before examination in fluorescence microscope under UV

Chemicals and solutions

  • DABCO: Diazabicyclo[2.2.2]octan (Sigma)
  • DAPI stock solution: 0.2 mg/ ml
  • 4',6-Diamidin-2-phenyl-indol2HClH20 (Serva) in Aqua dest.
  • Propidiumiodid stock solution: 1 mg/ml Propidiumiodid in Aqua dest.
  • staining solution: 20 µl DAPI stock solution and 20 µl PI stock solution in 60 ml PBS
  • PBS: 0.13 M NaCl, 0.007 M NaH2PO4, 0,03 M Na2HPO4, pH 7.4
  • Mounting medium, either: a) Vectashield (Serva) or b) 1 part Tris-HCl pH 7.4 and 9 parts Glycerin with 2.3% (w/v) DABCO and 0.02% NaN3

04/22/2024 9:23  Phaseolus polytene chromosomes by Mario Nenno. © 2008- All rights reserved.
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