Background: Current methods for the quantitative determination of glycogen in erythrocytes are unsatisfactory.
Methods: Erythrocytes were deproteinized with perchloric acid either after haemolysing by freezing and thawing twice or without freezing and thawing, and the glycogen content was determined by an enzymatic method.
Results: Freezing and thawing resulted in a significantly higher glycogen content, and the recovery of added glycogen using this method was nearly 100%. The mean erythrocyte glycogen content in healthy volunteers (n = 17) was 69.5 microg/g haemoglobin, a value much higher than the previously reported values in healthy subjects.
Conclusion: Freezing and thawing improves the assay of erythrocyte glycogen.