गुणसुत्रांना हलकेच गरम करुन गिएमसा रंजकाने रंगविल्यावर 'G' पट्टे निर्माण होतात.
(1) पश्चावस्था
(2) पूर्वावस्था
(3) मध्यावस्था
(4) अंत्यावस्था

The correct answer is Option C (Metaphase).

Key Points:
• G-Banding (Giemsa Banding): The standard cytogenetic karyotyping technique developed to produce alternating light and dark bands along the arms of mitotic chromosomes for identifying structural aberrations.
• Metaphase Chromosomes: Chromosomes reach their maximum level of structural condensation and distinct morphological alignment at the equatorial plane during the Metaphase stage of cell division, arrested using colchicine.
• Staining Technique: Chromosomes in Metaphase are subjected to mild enzymatic digestion (trypsin) or mild heat/saline and stained with Giemsa stain to reveal G-bands.
• Dark vs. Light Bands: Dark G-bands represent transcriptionally inactive, heterochromatic, AT-rich DNA, while light bands represent GC-rich, gene-dense euchromatin.
• Official Key: Metaphase corresponds to Option (3).
• Key Takeaway: G-banding is performed on highly condensed metaphase chromosomes using Giemsa stain for cytogenetic karyotyping.