Addition of Selective Agent

There are other factors that may affect the mutation frequency. We have already shown that the cell density, time of addition of selective agent (mutation expression), and concentration of selective agents can modify the final number of induced mutations. The following two situations may further decrease or increase the number of detectable mutations ... 

Sodium diethyldithiocarbamate, (C2H5)2N CS S Na+. This reagent is generally used as a 2 per cent aqueous solution it decomposes rapidly in solutions of low pH. It is an effective extraction reagent for over 20 metals into various organic solvents, such as chloroform, carbon tetrachloride, and ethanol. The selectivity is enhanced by the control of pH and the addition of masking agents. 

Can corrosion. This may be caused by incorrect pH of latex paints, or incorrect choice of ingredients leading to acidic by-products on storage. The remedy is careful selection of can lining, or perhaps the addition of anticorrosive agents to the paint, or improved formulation and adjustment. 

Table 2 lists the results found for the Grignard reagents investigated. In diethyl ether solution, the Grignard reagents preferentially add to C-1 [2], whereas in tetrahydrofuran (THF) and other solvents C-4 addition dominates [3], It was also reported that the addition of complexing agents such as iV,iV,iV, /V -tetramethylethylenediamine (TMEDA) or hexa-methylphosphoramide (HMPA) in diethyl ether resulted in the reversal of selectivity. 

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