Specific Banding Patterns of Human Chromosomes

Abstract

Individual pairs of human chromosomes can be reliably identified by a new method that does not require special optical equipment and that results in permanent preparations. This method, which is based on treatment of the chromosomes in situ with NaOH, followed by incubation in sodium chloride-trisodium citrate and Giemsa staining, results in highly specific banding patterns in characteristic regions of the chromosome arms. It should prove useful for the detection of small structural changes in chromosomes.During the past 15 years remarkable progress has been made in the descriptive morphology of both normal and abnormal human chromosomes, but with conventional cytological and autoradiographic techniques we have thus far failed to identify every chromosome in the human complement. Furthermore, these techniques have revealed very little differentiation within a chromosome arm, so that structural rearrangements that do not alter the length or centromere position, or produce only slight changes in these, will escape detection.Since the original description of specific fluorescent staining of human chromosomes (1), investigations have led to renewed hope for subdividing the classical chromosome groups into individual pairs. This paper describes a new method of differentiating human chromosomes that does not require fluorescence microscopy and that results in permanent preparations. The chromosomes exhibit banding patterns in specific regions. In addition to the sex chromosomes, 20 of the 22 autosomal pairs have been identified by this technique, and the remaining two are tentatively classified. MATERIALS AND METHODSLymphocyte and fibroblast cultures from normal persons were prepared and harvested in the usual manner. Colchicine, 0.04 /Ag/ml of medium, was added to the cultures 2 and 6 hr before harvest. After hypotonic treatment with 1% sodium citrate and fixation in methanol-acetic acid 3:1, flame-dried slides were prepared. The method to be described consists of treatment of the chromosomes in situ with NaOH, followed by incubation in several concentrations of a saline-citrate solution (SSC). Specific regions of the chromosome arms then stain differentially with buffered Giemsa. Because a number of parameters have varied in our pilot experiments and we do not yet know the optimal conditions for treatment, we will present first a basic procedure that we have found to produce bands fairly consistently, and then a range of times and concentrations that have been tested.The slides are treated for 30 sec in a solution of 0.07 N NaOH in 0.112 M NaCl (pH 12.0) at room temperature and then rinsed three times in 12 X SSC (pH 7.0) for 5-10 min each time. They are then incubated in 12X SSC at 650C for 60-72 hr. After incubation, the slides are passed through three changes of 70% ethanol and three changes of 95% ethanol (3 min each). After air-drying, slides are stained for 5 min in buffered Giemsa solution (pH 6.6), rinsed briefly in distilled water, air-dried again, and mounted in Permount.The alkaline solution is pr...

Differential staining of cultured bone marrow cell chromosomes of Rana pipiens.

“…G-banding produces distinct bands along the entire chromosome with various post-fixation treatments followed by Giemsa staining. G-banding has been elicited through post-fixation treatment with alkaline-saline (Drets andShaw 1971, Schnedl 1971), acid-saline (Gagne et al 1971, Sumner et al 1971), Giemsa 9 staining (Patil et al, 1971), pro nase (Dutrillaux et al 1971), trypsin (Wang and Federoff 1972, Seabright 1972, Sun et al 1974, urea (Shiraishi and Yosida 1972), potassium permanganate (Uta koji 1972, Matsukuma and Utakoji 1976), and caesium chloride (Meisner et al 1973). R-banded chromosomes, which show a pattern the opposite of G-banding, have also been described (Dutrillaux and Lejeune 1971, Verma and Lubs 1975.…”

Tools and methodologies for cytogenetic studies of plant chromosomes

“…Each of the protocols, by using a variety of treatments before fixing chromosomes and staining with Giemsa, yielded a banding pat tern in normal mitotic chromosomes that was sim ilar to the one revealed by the Q banding tech nique. The dark regions are the topological equivalents to Q bands and are called G bands whereas the light regions are equivalent to the nonfluorescent dark ones revealed with the use of fluorescent dyes (Drets and Shaw, 1971;Dutrillaux and Lejeune, 1975). Application of G banding methods to prophase and prometaphase chromo somes in animals revealed a larger number of bands than at metaphase which permited more precise karyotyping and cytogenetic analysis (Yunis, 1981;Iannuzzi, 1990).…”

Chromosome Bands Induced in Human and Syrian Hamster Cells by Chemical Carcinogens

“…DURING THE past 3 years a number of techniques have been developed for distinguishing between morphologically similar chromosomes according to the banding pattern which formed after special treatments of fixed chromosomes (Caspersson, Johnanson and Modest, 1970;Sumner, Evans and Buckland, 1971;Drets and Shaw, 1971;Seabright, 1971). The bands, generally referred to as G or Q, represent specific regions of the chromosomes that become swollen and show transverse ridges which take up and bind dyes.…”