Restriction enzyme help

Cornelius Krasel zxmkr08 at
Sun Apr 4 16:05:52 EST 1993

In <nash.88.0 at> nash at (John Nash) writes:

>In article <1993Apr2.181617.15803 at> abigail at (Shawn Abigail) writes:
>>C, T, A & G are obvious!  R stands for a Purine and Y stands for a
>>Pyrimidine.  Does N stand for "any nucleotide"?  What about W and S?
>>Any help is gratefully appreciated.

Some help for memorizing the ambiguity abbreviations:

>R = A or G	Y = T or C
 R = puRine     Y = pYrimidine

>W = A or T	S = G or C
 W = Weak       S = Strong (A and T make two H bonds, G and C three)

>M = A or C	K = G or T

>H = A or T or C
 H comes after G, which is not in the list

>B = C or T or G
 B comes after A

>V = A or C or G
 V comes after T (if you don't count U which stands for uracil)

>D = A or G or T
 D comes after C

>N = A or C or G or T
 N = aNy (not too complicated :-)

/* Cornelius Krasel, Department of Physiological Chemistry, U Tuebingen    */ 
/* email: krasel at                             */
/* "People are DNA's way of making more DNA." (R. Dawkins / anonymous)     */

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