PsbD | D2 protein of PSII positive control/quantitation standard

D2 protein (PsbD) forms the reaction core of PSII (Photosystem II) as a heterodimer with the D1 protein (PsbA) . PsbD is homologous to the D1 protein, with slightly higher molecular mass of about 39.5 kDa. Accumulation of D2 protein is an important step in the assemply of the PSII reaction centre complex.This product is a recombinant protein standard, source Synechocystis strain PCC 6803.

Standard curve: 3 loads are recommended (0.5, 2 and 4 μl) .For most applications a sample load of 0.2 μg of chlorophyll will give a PsbD signal in this range.Positive control: a 2 μl load per well is optimal for most chemiluminescent detection systems. This standard is stabilized and ready and does not require heating before loading on the gel.Please note that this product contains 10% glycerol and might appear as liquid but is provided lyophilized. Allow the product several minutes to solubilize after adding water. Mix thoroughly but gently Take extra care to mix thoroughly before each use, as the proteins tend to settle with the more dense layer after freezing.

For reconstitution add 225 µl of sterile water, Please notice that this product contains 10% glycerol and might appear as liquid but is provided lyophilized

Concentration:after adding 225 µl of milliQ water final concentration of the standard is 0.25 pmoles/ulProtein standard buffer composition: Glycerol 10%, Tris Base 141 mM, Tris HCl 106 mM, LDS 2%, EDTA 0.51 mM, SERVA® Blue G250 0.22 mM, Phenol Red 0.175 mM, pH 8.5, 0.1 mg/mL PefaBloc protease inhibitor (Roche), 50 mM DTT.This standard is ready-to-load and does not require any additions or heating. It needs to be fully thawed and thoroughly mixed prior to using. Avoid vigorous vortexing, as buffers contain detergent. Following mixing, briefly pulse in a microcentrifuge to collect material from cap.This standardis stabilized and readyand does not require heating before loading on the gel.Please note that this product contains 10% glycerol and might appear as liquid but is provided lyophilized. Allow the product several minutes to solubilize after adding water. Mix thoroughly but gently Take extra care to mix thoroughly before each use, as the proteins tend to settle with the more dense layer after freezing.

The PsbD protein standard can be used in combination with global anti-PsbD antibodies to quantitate PsbD from a wide range of species. Global antibodies are raised against highly conserved amino acid sequences in the PsbD protein.Quantitative western blot: detailed method description, video tutorial

Partensky et al. (2018) . Comparison of photosynthetic performances of marine picocyanobacteria with different configurations of the oxygen-evolving complex. Photosynth Res. 2018 Jun 25. doi: 10.1007/s11120-018-0539-3.Li et al. (2016) . A Hard Day's Night: Diatoms Continue Recycling Photosystem II in the Dark. Front. Mar. Sci., 08 November 2016Li et al. (2014) . The nitrogen costs of photosynthesis in a diatom under current and future pCO2. New Phytol. 2014 Sep 25. doi: 10.1111/nph.13037.

Store lyophilized/reconstituted at -20°C; once reconstituted make aliquots to avoid repeated freeze-thaw cycles. Please remember to spin the tubes briefly prior to opening them to avoid any losses that might occur from material adhering to the cap or sides of the tube.