# Alternative Agents to Colcemid for Obtaining High-Quality Metaphase Spreads

## TL;DR

This study finds that Org9935 and Griseofulvin are better than colcemid for creating long chromosomes needed for FISH experiments in cytogenetics.

## Contribution

The study identifies Org9935 and Griseofulvin as superior alternatives to colcemid for generating longer chromosomes in metaphase spreads.

## Key findings

- Org9935 and Griseofulvin produced longer chromosomes compared to colcemid.
- Seven alternative substances were tested for their effectiveness in cytogenetics.
- Lymphocyte cultures from whole blood were used to evaluate the substances.

## Abstract

This study analyzes the effectiveness of different substances in producing longer chromosomes for FISH experiments in cytogenetics. Traditionally, colcemid is used, but researchers tested seven alternatives, demonstrating that some are more effective. In particular, Org9935 and Griseofulvin proved to be the best at generating longer chromosomes.

In cytogenetics, the ability to perform FISH (Fluorescence In Situ Hybridization) experiments using probes that map very closely together depends on the capacity to produce sufficiently long chromosomes. Traditionally, colcemid is the chemical agent used to obtain metaphase spreads. However, various substances have been reported to arrest cells in an earlier stage of mitosis than the metaphase, potentially providing longer chromosomes. In this study, we tested seven substances different from colcemid, which, according to the literature, have this capability: Vinblastine, Combretastatin A-4, Podophyllotoxin, Org9935, Nocodazole, Paclitaxel, and Griseofulvin. All substances were tested on lymphocyte cultures derived from whole blood at the same concentration: 0.1 µg/mL. Among these, Org9935 and Griseofulvin were confirmed to have the ability to produce metaphases with longer chromosomes compared to those obtained with colcemid.