cdna library. - (Dec/12/2011 )

hello everyone
i' constructed cdna library using clontech kit. but i didn't get any result when i used my stored competent cells which i made 4days, back stored in -80i.e colonies neither in control nor in negative (only competent cell). freshly prepared cells gave me results. it made electrocompetents. and during first transformation i we gave electric pluse of 1800voltsand during second transformation gv 1700 volt pluse.
now i'm confused is there any problem with my competent cells or in giving pluse or is there anyother problem. so please help me.

There are two types of competent cells, which have different preparation procedures: those that can be frozen and those that must be used fresh. You should check which type you are using.

hi bob1 thanx for ur reply.the protocol i'm following has mentioned that i can store my competent cells and reused them. i made electrocompetent cell using 10% glycerol.plz help me .