Potassium cacodylate

Equilibration buffer contains potassium cacodylate (dimethylarsinic acid). Avoid contact with skin and eyes. Harmful if swallowed. Wear appropriate protective clothing. 

Dilute the RNA solution (10—50 jxM) in CEK buffer (10 mM potassium cacodylate, 0.1 mM EDTA at pH 7.3, 100 mM KC1) for Mg2-1-titration or in 1 X CE buffer (for monovalent ion titration). We consis-tendy get good results with RNA concentrations corresponding to an absorbance of 0.5—0.6 O.D. Prepare RNA in appropriate amounts for up to three folding data points for each centrifuge run. 

Potassium ferrioyanide. Potasaiumferrocyanide, dieacodyl, potassium cacodylate. 

Potassium cacodylate, (CIl3)2As02K.ll20. A very d< lisparingly soluble in alcohol, insoluble in ether." 11 forms a molybdenum salt with molybdie acid, whieh crystallises in ne<"dl< s of composition ... 

TdT reaction buffer supplied with the TdT enzyme as a 5X concentrated solution (5X concentrated= 1 M potassium cacodylate, 125 mM Tris-HCl, pH 6.6, 1.25 mg/mL bovine serum albumin [BSA]) and stored at -20°C. 

Terminal deoxynucleotidyl transferase (Gibco BRL, Grand Island, NY). Labeling buffer (5X 500 mM potassium cacodylate, pH 7.2, 1 mM DTT). Store at -20°C. 

Terminal deoxynucleotidyl transferase (TdT) 15U/pL and 5X reaction buffer 0.5M potassium cacodylate (pH 7.2), lOtnM cobalt chloride, 1 mAf DTT (Gibco-BRL 18008-011). 

Terminal deoxynucleotidyl transferase (TdT, 10-20 U/pL) can be purchased from Gibco-BRL. The enzyme is supplied with a vial of 5X reaction buffer (500 mM potassium cacodylate, pH 7 2, 10 mM C0CI2,1 mM DTT) Store at -20°C. Note that potassium cacodylate and C0CI2 are highly toxic and should be handled with care... 

FIGURE 8.9. Comparison of various properties of tRNA s as a function of temperature, (a) Optical melting curves of three purified yeast tRNA s in 0.15 M NaCI, pH = 7 (b) temperature dependence of absorption ( ) and sedimentation coefficient (o) (at infinite dilution) and (c) intrinsic viscosity of yeast tRNA (unfractionated) in 0.15 M KCi, 0.01 M potassium cacodylate, 0.005 M MgCl2, and 0.0005 M EDTA (d) valine acceptor activity (squares) and absorption (circles) of unfractionated E. coli tRNA as a function of temperature. Conditions 0.05 M sodium cacodylate, pH 6, 0.01 M MgCIg. [(a) from Ref. 11 (b), (c), and (d) from Ref. 20.]... 

CAUTION CaCl, CO, ether, formaldehyde, KCl, MgCl, paraformaldehyde, potassium cacodylate (see Appendix 4)... 

Cacodylate contains arsenic, is highly toxic, and may be fatal if inhaled, ingested, or absorbed through the skin. Wear appropriate gloves and safety glasses and use in a chemical fume hood. See also Potassium cacodylate Sodium cacodylate. 

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