public static boolean isAmbiguous(String sequence) {
		char seq[] = sequence.toLowerCase().toCharArray();
		for (int i = 0; i < seq.length; i++) {
			char c = seq[i];
			if ((c != 'a') && (c != 'c') && (c != 'g') && (c != 't')) return true;
		}
		return false;
	}