|Types of controls||Description||Catalog#||Pack||Price $|
|EMSA-P/N Ctrl||EMSA Positive/Negative||SERV05a
|EMSA-P/ Ctrl||EMSA Positive controls||SERV05b
|EMSA-N/ Ctrl||EMSA Negative controls||SERV05c
EMSA is a well-established technique for detecting the activity of DNA/RNA-binding proteins. As other gel electrophoresis, a reference standard is important to locate the target molecule. However, common standards used in Western blots or molecular size markers for DNA/RNA electrophoresis can not be used for EMSA because the location of DNA/RNA-binding proteins is based to the combination of shape, size, charge and interaction of the native proteins. The use of EMSA controls in EMSA can save time and precise location of target proteins.
Some EMSA kits contain controls. For example, Light Shift kit includes EBNF controls. However, EBNF control is not a good one for following reasons:
1. EBNF band locates at the
position just above free probes, much
smaller that that of most nucleic acid-protein
complexes. It is too
small to locate most of target proteins.
2. Probes & samples of EBNF control are completely different from that customer want to use, therefore, the control cannot provide information for the real reaction of target probes & samples. If specific shifted bands cannot be observed, the problems could be 1) low level of nuclear extracts, 2) proteins degradation, 3) inactivated protein factors or 4) non-working probes etc, no of which has relationship with EBNF controls.
3. EBNF control was considered to be an indicator for working EMSA as EBNF band cannot be seen if electrophoresis, trans-blotting, UV crosslinking, biotin/avidin reaction, reagents or non-working ECL substrates etc. do/does not work. However, if problems mentioned above happen, free probe bands could not be seen either. Since free probes can be used as indicators, why needs EBNF control.
4. EMSA pictures with free probe lane(s) can be used for publication directly, however, it would be strange if EMSA pictures include EBNF band(s).
Viagene Biotech Biotech provides largest number of EMSA negative/positive controls than other companies; such as NFkB/NK-kB, AP1, SP1, OCT1, OCT2, NRF2, GATA, STATs, WT-1, E2F, P53...