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Total Protein Kit, Micro-Lowry, Onishi & Barr Modification

sufficient for ~50 manual assays

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wavelength 500-750nm

Quality Level


sufficient for ~50 manual assays

protein detection level measuring range

0-1 mg/mL


18-26 °C temperature
200 μL sample volume

storage temp.


General description

The biuret and Lowry procedures are used for protein determination. The former is widely used for clinical assays. The latter, though more sensitive, is used for investigative work and is limited by poor stability of combined reagents, non-reproducibility of color, especially at low protein concentration, and nonlinear chromogenic response with protein concentration. Ohnishi and Barr modified the biuret reagent for the Lowry procedure, thereby simplifying it while improving the stability of the combined reagent.


Total Protein Kit, Micro-Lowry, Onishi & Barr Modification has been used to determine total soluble protein concentrations:
  • in the dialyzates/extracts of gliadins
  • in the extracts of flour (Avena sativa and Triticum durum) and seeds (Chenopodium quinoaSalvia hispanica L.)
  • in the stored samples of rat liver microsomal fractions


Colorimetric, Endpoint.assay. Ohnishi and Barr′s modification of micro Lowry method. According to procedure, dilute biuret reagent reacts with peptide bonds to yield a purple-blue complex, the color of which is intensified by the addition of phenol reagent. Absorbance, read at 550-750 nm, is used to determine results from a standard curve.

Kit Components Also Available Separately

Product No.

  • B3934Biuret reagent, protein detection level 150-1,000 μg/mL 110 mLSDS

  • Folin & Ciocalteu’s phenol reagent 5 mL

  • Protein standard 5 mL





Hazard Classifications

Eye Dam. 1 - Met. Corr. 1 - Skin Corr. 1

Storage Class

8A - Combustible, corrosive hazardous materials




Not applicable


Not applicable

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David Kessel
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When the initial effect of photodynamic therapy (PDT) involves mitochondrial photodamage, an early effect is loss of the mitochondrial membrane potential (ΔΨm ). Using murine hepatoma 1c1c7 cells and a photosensitizing agent known to target mitochondria, we examined loss of
A Smialowska et al.
Journal of dairy science, 100(4), 2553-2563 (2017-02-22)
We isolated goat phosphopeptides via calcium and ethanol precipitation from a caseinate digest and investigated their feasibility as an iron-fortification ingredient in nutritional foods. Goat tryptic-digested phosphopeptides could bind 54.37 ± 0.50 mg of Fe/g of protein compared with goat
Bartosz Fotschki et al.
Molecules (Basel, Switzerland), 23(9) (2018-08-24)
The aim of this in vitro study was to examine the effect of raspberry polyphenolic extract on the immune-metabolic molecular mechanisms activated by obesity-related signals in hepatocytes (HB-8965®). Alterations in endosomal/lysosomal activity (neutral red uptake assay, NR), the expression of
Jose Laparra et al.
Oncotarget, 10(7), 760-772 (2019-02-19)
Imbalances in innate immunity and the activity of innate immune cells are implicated in the development of hepatocellular carcinoma (HCC). Plant seeds are good sources of protease inhibitors, which can have a significant influence on human health disorders, especially in
Parisa Yousefpour et al.
International journal of nanomedicine, 6, 1977-1990 (2011-10-07)
Targeting drugs to their sites of action to overcome the systemic side effects associated with most antineoplastic agents is still a major challenge in pharmaceutical research. In this study, the monoclonal antibody, trastuzumab, was used as a targeting agent in

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