private static char[] getColumn (Alignment layoutMap, int index) {
		List<Read> reads = new ArrayList<Read>();
		for (Read lay : layoutMap.values()) {
			if (lay.getOffset() <= index && index < lay.getOffset() + lay.getLength()) {
				reads.add(lay);
			}
		}
		
		char[] column = new char[reads.size()];
		for (int i = 0; i < reads.size(); i++) {
			Read read = reads.get(i);
			char c = read.sequence.get(index - read.getOffset());		
			column[i] = c;
		}
		return column;
	}