The BLUelf Prestained Protein Ladder is a three-color protein standard with 13 prestained proteins covering a wide range molecular weights from 3.5 to 245 kilodalton (kDa). Proteins are covalently coupled with a blue chromophore except for two reference bands (one green and one red band at 25 kDa and 75 kDa respectively) when separated on SDS-polyacrylamide gel electrophoresis (SDSPAGE) with Tris-glycine-SDS running buffer. The BLUelf Prestained Protein Ladder is designed for monitoring protein separation during SDS-PAGE, verification of Western transfer efficiency on membranes (PVDF, nylon, or nitrocellulose) and for approximating the size of proteins. The ladder is supplied in gel loading buffer and is ready to use. Do not heats, dilute, and add reducing agent before loading.
- Broad range: 3.5-245 kDa (Tris-glycine-SDS running buffer)
- Ready-to-use: supplied in a loading buffer for direct loading on gels
- Easy to identify: includes the ~25, ~75 kDa reference bands coupled with a green and a red dye
- Sharp bands
- Monitoring of protein migration during SDS-PAGE.
- Monitoring of protein transfer onto membranes during Western blots.
- Sizing of proteins on SDS-PAGE and Western blots.
Approximately 0.1~0.4 mg/ml of each protein in the buffer (20 mM Tris-phosphate, pH 7.5 at 25°C), 2 % SDS, 0.2 mM Dithiothreitol, 3.6 M Urea, and 15 % (v/v) Glycerol.
The quality of the BLUelf Prestained Protein Ladder is tested on a lot-to-lot basis to ensure consistent product quality.
BLUelf Prestained Protein Ladder Protocol
1. Thaw the ladder either at room temperature or at 37-40°C for a few minutes to dissolve precipitated solids. Do not boil.
2. Mix thoroughly to ensure the solution is homogeneous.
3. Load the following volumes of the ladder on SDS-PAGE gel:
- 5 μl per well for mini-gels, 2.5 μl per well for blots
- 10 μl per well for large gels, 5 μl per well for blots
- Apply more for thicker (> 1.5 mm) or larger gel
Guide for Molecular Weight Estimation (kDa)
Migration patterns of BLUelf Prestained Protein Ladder in different electrophoresis conditions are listed below:
1. The apparent molecular weight of each protein has been determined by calibration against unstained protein standards
2. Supplemental data should be considered for more accurate adjustment in different electrophoresis conditions.
All products are for research use only.
Caution: Not intended for human or animal diagnostic or therapeutic uses.