QFQ-BANDING

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I. Purpose

A. Identification of individual chromosomes and their struc-
tural anomalies

II. Procedure

A. Culture and harvest according to the standard procedure.
The slides can be stained as soon as they have dried.

B. Staining procedure

1. Place slides for 1 minute in a Coplin jar containing
40 ml of quinacrine mustard stain solution.

2. Rinse slides by dipping repeatedly in deionized water.

3. Place slides for 1 minute in a Coplin jar containing
40 ml of Sorensen buffer pH 6.8.

4. Apply coverslip while slide is still wet with buffer.

5. Remove excess buffer from under the coverslip by press-
ing lightly with the thumb on the coverslip and blot-
ting around its edges with a paper towel.

6. The slide can be analyzed immediately or the cover-
slip can be sealed with clear fingernail polish and
analyzed up to 24 to 48 hours later. It is best to
refrigerate the slide if it will not be examined
within a couple of hours.

C. Microscopy

1. Use a microscope equipped with an incident-light
fluorescence system. For example, use a 200-watt
mercury light source, a blue light-excitor filter
(490 nanometers), and a barrier filter (510 nanometers).


REFERENCE

1. Caspersson T, Zech L, Johansson C: Differential binding of
alkylating fluorochromes in human chromosomes. Exp Cell Res 60:315-319, 1970 [Our method is a modification of the one described in this paper].

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