[RoseZ]

Hi,

I am having trouble with the Megazyme kit (K-SUFRG) for sucrose, glucose, fructose.  The kit is specific for gluctose and fructose, but sucrose is not measured independently.  The response for glucose (ΔAgluc) is subtracted from the response for sucrose (ΔA total glucose) and this is resulting in low and even negative values for sucrose.  I am trying to measure gluc, fruc, suc in sweet potato extracts and sucrose is expected to be the predominant sugar.  But my values for sucrose are usually lower than fructose and glucose.

Is anyone familiar with this kit?  Please help.

Thank you,
Rose

[Babcock_Hall]

I am not familiar with this kit.  Would you provide some more details?  The method of analysis and the equations would help.

[RoseZ]

Thanks for your reply.  Yes, I will give more information.  Rather than type everything out, here is a link to the booklet for the kit which explains all of the reactions.  http://secure.megazyme.com/files/BOOKLET/K-SUFRG_1212_DATA.pdf

I have sweet potato samples that have been freeze-dried and then ground to a fine powder.  The sweet potato flour is then extracted with water (~35mg powder to 1mL water).  This extract is used then with the kit directly.  The directions in the booklet are for using a spec, but I have scaled down everything 10-fold for use with a plate reader.

Thanks,
Rose

[Babcock_Hall]

I am a little bit behind at work, but I will respond as soon as I can.