Pullulanase/Limit-Dextrinase Assay Kit (PullG6 Method)

PullG6 assay for the measurement of pullulanase employs a water soluble defined substrate, namely 4,6-O-benzylidene-4-nitrophenyl-63-α-D-maltotriosyl-maltotriose (BPNPG3G3), coupled with the ancillary enzymes α-glucosidase and β-glucosidase. Upon hydrolysis of the substrate at the 1,6-α-linkage by pullulanase or limit-dextrinase, the released 4-nitrophenyl-β-maltotrioside is immediately hydrolysed to glucose and 4-nitrophenol by the concerted action of the α-glucosidase and β-glucosidase enzymes in the reagent mixture. The reaction is terminated and phenolate ions are developed by addition of dilute alkali. The absorbance is read at 400 nm and the value obtained correlates directly with pullulanase activity.

Product Code
100 / 200 assays per kit

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Colourimetric method for the determination of pullanase
or limit-dextrinase

(1) Benzylidene-G3-(α-1,6)-G3-β-PNP + H2O → Benzylidene-G3
                                                                           + G3-β-PNP

  (thermostable α-glucosidase and β-glucosidase)
(2) G3-β-PNP + H2O → D-glucose + PNP

    (alkaline solution)
(3) PNP → phenolate ion (yellow colour)

Note: PNP = 4-nitrophenol

Kit size:                             100 / 200 assays
Method:                            Spectrophotometric at 400 nm
Total assay time:               10 min for pullanase preparations
                              30 min for malt extracts containing
Detection limit:                  0.18 U/mL for pullulanase preparations
(50-fold dilution)
               0.01 U/g for limit dextrinase in milled malt
Application examples: Assay of microbial pullulanase preparations
Measurement of limit-dextrinase in
malt extracts
Method recognition:     Novel method


  • High sensitivity
  • Suitable for manual and auto-analyser formats
  • No transglycosylation interference
  • Very cost effective
  • All reagents stable for > 1 year after preparation
  • Very specific

  • Simple format

  • Standard included

Prediction of potential malt extract and beer filterability using conventional and novel malt assays.

Cornaggia, C., Evans, D. E., Draga, A., Mangan, D. & McCleary, B. V. (2019). Journal of Institute of Brewing, In Press.

Colourimetric and fluorometric substrates for measurement of pullulanase activity.

McCleary, B. V., Mangan, D., McKie, V., Cornaggia, C., Ivory, R. & Rooney, E. (2014). Carbohydrate Research, 393, 60-69.

Colourimetric and fluorimetric substrates for the assay of limit dextrinase.

Mangan, D., McCleary, B. V., Cornaggia, C., Ivory, R., Rooney, E. & McKie, V. (2015). Journal of Cereal Science, 62, 50-57.

Gluten-free sources of fermentable extract: effect of temperature and germination time on quality attributes of teff [Eragrostis tef (zucc.) trotter] malt and wort.

Di Ghionno, L., Marconi, O., Lee, E. G., Marconi, O., Rice, C. J., Sileoni, V. & Perretti, G. (2017). Journal of Agricultural and Food Chemistry, 65(23), 4777-4785.

Optimization of the production of an extracellular and thermostable amylolytic enzyme by Thermus thermophilus HB8 and basic characterization.

Akassou, M. & Groleau, D. (2017). Extremophiles, 1-14.

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