Table 1.

Allele Mobility in Standard and 40% Formamide Gels

Sample	A. Standard gels apparent size range (bp)		B. Formamide gels apparent size range (bp)		C. (CG)7-8 allele sequence length (bp)	D. (CG)5 allele sequence length (bp)
varying allele	stable allele	varying allele	stable allele
1	145–153	145	145–155	145	155 (153, 151)a	145
2	150–153	153	150–155	153	155	153
3	149–152	149	149–155	149	155	149

Apparent sizes of the variable- and stable-mobility alleles in the three individuals heterozygous for variable-mobility alleles are shown, as determined using standard (column A) and 40% formamide (column B) gels. Three control individuals without variable-mobility alleles were also typed as references. The relative mobility of their alleles did not change (see Fig. 1 for examples). The length of the (CG)_7–8 and (CG)₅ alleles, as determined by sequencing, are also shown. The variable-mobility allele present in sample 1 appeared to be 145 bp in size only twice and never electophoresed so rapidly in either sample 2 or 3; as this individual has a stable allele of 145 bp, this result may be due to lack of PCR of this allele in these two instances. 

^aDue to variation in number of repeats in the sequenced clones of this allele, the allele length is uncertain but most likely is 155 bp.