Formula weight for 3-O-methyl-D-glucose: 194.18grams
Formula weight for L-rhamnose: 182.17 grams
Protocol (Lutgens et al):
(1) The patient fasts overnight.
(2) The urinary bladder is voided.
(3) The patient drinks 0.2 grams OMG and 1.0 grams of L-rhamnose (often mixed with other sugars such as D-xylose and lactulose, see previous sections) in an isotonic solution.
(4) Urine is collected for the next 5 hours.
(5) A light breakfast is permitted 2 hours after drinking the solution.
(6) The volume of the urine at 5 hours is measured and an aliquot is sent for testing.
(7) Measure the amount of L-rhamnose and OMG in the urine.
urine excretion of L-rhamnose in mg =
= (urine L-rhamnose in mg/dL) * (urine volume in mL) / 100
percent of oral dose of L-rhamnose in the urine =
= (urine excretion of L-rhamnose in mg) / 1000 * 100%
urine excretion of OMG in mg =
= (urine OMG in mg/dL) * (urine volume in mL) / 100
percent of oral dose of OMG in the urine =
= (urine excretion of OMG in mg) / 200 * 100%
rhamnose to OMG ratio =
= (percent of oral dose L-rhamnose in urine) / (percent of oral dose OMG in urine)
Interpretation:
• The normal L-rhamnose to OMG ratio is >= 0.65
