PCR 反应增强剂
1.DMSO and glycerol
Recommended by a number of authors to improve amplification efficiency and specificity of PCR. However,in the multiplex reaction these enhancers gave conflicting results.For example,5% DMSO improved the amplification of some products , decreased the amount of others and some loci were not affected at all. The same observations were made with 5% glycerol.
2.Bovine Serum Albumin (BSA)
100 μg/ml - 1 ug/ul,0.01% - 0.1% (w/v)
The addition of albumin to tissue DNA samples increases the amount of DNA generated by neutralizing many deleterious factors found in tissue samples which can inhibit PCR. Concentrations of up to 0.8 μg/μL may increase the efficiency of a PCR reaction much more than either DMSO or glycerol.
3.Formamide
1.25% - 10% (v/v)
In regions of high G/C content,specificity is reduced and multiple bands are observed when PCR products are separated on an agarose gel. Formamide enhances specificity and yield by changing the Tm of the primer-template hybridization reaction and lowers enzyme resistance to heat destruction. However,formamide can also be inhibitory to DNA polymerases so it needs to be tested at various concentrations to determine its optimal concentration levels.
4.PEG (polyethylene glycol) 6000
5%-15% (w/v)
5.Spermidine
Reduces non-specific reactions between the polymerase and DNA.
· Tris-HCl: 10 mM - 67 mM, pH 8.2 - 9.0
· KCl: 25 mM - 50 mM
· MgCl2: 1.5 - 5.0 mM
· Gelatin: 0.01% - 0.1% (w/v)
· Non-ionic detergents
· Tween 20: 0.05% (v/v)
· Triton-X-100: 0.01% (v/v)
· Tetramethyl ammonium bromide
· TMANO (trimethylamine N-oxide)
· Betaine