Western blot of transfected CHO cells containing 50 units of MUG activity each: WT, wild-type Hex S; NK, Hex S containing a Arg424 → Lys substitution; DR, Hex S containing a Asn423 → Asp substitution; NQ, Hex S containing a Arg424 → Gln substitution. Sandhoff is a positive control lane containing lysate from a Sandhoff patient’s fibroblasts, and Neg is the negative control lane containing untransfected CHO cell lysate. The output from Gel Plot Macro of NIH Image 1.60 software is presented as an insert near the bottom of the membrane, and the calculated Areas are reproduced in a larger font size below the scans of each mature αCRM band. Note that the Image program divided the smallest NQ band into two sections. Only the sum of these sections (480) is shown in larger size font below.