Dot-it-Spot-it® Protein Assay

Bovine serum albumin (BSA)

BSA calibration standard was diluted between 0.16-20 μg BSA/mL.
The sample buffer was 0.03% Tween 20, 20 mM TRIS pH 7.5, 0.15 M NaCl.

Dot-it-Spot-it analysis:
1μL of application mixture containing 50% Dilution buffer+50% sample.

A. Semiquantitative detection by eye.
Position 9 and 18 contain 10 ng BSA, which is 1:2-diluted down to 0.08 ng BSA (position 2, 11).
The background signal, without BSA, is shown in position 1 and 10.

B. Quantitative detection with scanner, Epson Perfection V600 Photo, using Epson Scan software.
The BSA dilution series between 0.16 to 20 microgram/mL gives a signal with the unit delta blackness per pixel (dbpp).
In the inserted graph is shown the low signal range with the background signal as a dashed line.


Results on the Detection sheet.
Position 1-9, 10-18: 0, 0.08, 0.16, 0.31, 0.63, 1.25, 2.5, 5 and 10 ng BSA per dot.



Studies that have been using Dot-it-Spot-it Protein Assay

2014  Intracellular concentration of the tyrosine kinase inhibitor imatinib in gastrointestinal stromal tumor cells.  Anticancer Drugs. 2014 Apr;25(4):415-22.
Berglund E, Ubhayasekera SJ, Karlsson F, Akcakaya P, Aluthgedara W, Ahlen J, Fröbom R, Nilsson IL, Lui WO, Larsson C, Zedenius J, Bergquist J, Bränström R.

2015  High-abundant protein depletion strategies applied on dog cerebrospinal fluid and evaluated by high-resolution mass spectrometry.  Biochemistry and Biophysics Reports. 2015, 3, 68-75.
Sundberg, M., Bergquist, J., Ramström, M.

2015  A proteomic approach to monitor the dynamic response of the female oviductal epithelial cell surface to male gametes.  Journal of proteomics. 2015, 113, 1-14.
Artemenko, K., Horakova, J., Steinberger, B., Besenfelder, U., Brem, G., Bergquist, J., Mayrhofer, C.

2016  Analysis of the cerebrospinal fluid proteome in Alzheimers´s disease.  PLOS ONE. 11(3) e0150672.  DOI:10.1371/journal.pone.0150672 March 7, 2016
Khoonsari, P.E., Häggmark, A., Lönnberg, M., Mikus, M., Kilander, L., Lannfelt, L., Bergquist, J., Ingelsson, M., Nilsson, P., Kultima, K., Shevchenko, G (2016).

2016  Lipodisks integrated with weak affinity chromatography enable fragment screening of integral membrane proteins.  Analyst. 2016, 141, 981-988.
Duong-Thi, M-D., Bergström, M., Edwards, K., Eriksson, J., Ohlson, S., To Yiu Ying, J., Torres, J., Agmo Hernández, V.

2018  Improved efficiency of in situ protein analysis by proximity ligation using UnFold probes. Scientific Reports volume 8, Article number: 5400 (2018). DOI:10.1038/s41598-018-23582-1.
Klaesson, A., Grannas, K., Ebai, T., Heldin, J., Koos, B., Leino, M., Raykova, D., Oelrich, J., Arngården, L., Söderberg, O., Landegren, U.