Introduction:

Blue Prestained Protein Marker (3.3-31 kDa) is a mixture of five blue-stained proteins ranging from 3.3 to 31 kDa for use as size standards in protein electrophoresis (Tricine SDS-PAGE) and western blotting. Five clear blue protein bands can be visualized directly in SDS-PAGE gels or transfer membranes. The protein marker can be used to directly observe protein electrophoresis and clearly judge the transfer effect of western blotting. The concentration of each band is about 0.2 mg/mL.

Storage:

Store at -20℃ for one year.

Notes:

1. Thaw the ladder at room temperature before use, please do not heat it at 100℃. 
2. The preparation and operation of Tricine SDS-PAGE is far more complicated than the conventional SDS-PAGE method. It is recommended to use WSHT’s tricine precast gel (Cat. #: TCH2001-16.5T).
3. Since the number of amino acids contained in the polypeptide is small, if the polypeptide contains too many polar amino acids (basic or acidic), it will affect the band mobility on the SDS-PAGE chart. That is to say, its apparent molecular weight may have a certain distance from the theoretically estimated molecular weight of amino acids of the polypeptide.
4. On the SDS-PAGE map, the molecular weight range of the linear relationship between the logarithmic molecular weight and the mobility of the protein is 15,000 Da-200,000 Da. Therefore, for the molecular weight of a protein or polypeptide with a molecular weight of less than 10,000 Da, it can only be estimated based on the standard molecular weight to infer whether it falls within the predicted molecular weight range.
5. Since ultra-low molecular weight polypeptides (3000 and below) are easily leached from the gel, the dyeing and decolorization time should not be too long, and the gel should not be soaked in water for too long after decolorization, otherwise the bands will disappear.
6. For research use only. Not for use in diagnostic procedures.

Protocol:

1. The protein ladder is supplied in a ready-to-use format for direct loading onto gels; no need to heat, reduce, or add sample buffer prior to use.
2. Load 5 -10 μL of protein marker for each lane.