I think following happens. lid 85deg ; Wait; Auto : preheats the PCR device to 85 deg and hold the temp at 85  95deg 5min temp goes up to 95 and stays there for 5 min 95deg 30 sec Cycle begins. First step is to heat the sample upto 95 deg and hold it for 30 sec 40deg 60 sec Second step of the cycle. Temp is lowered to 40 deg and holds at 40 for 60 sec 72deg 30 sec THird step. Temp goes up to 72 and hols the sample for 30 sec at 72. 1 Cycle ends. Goto 2 rep 40 times Repeats the above cycle for 40 times 72deg 5 minutes After 40 repeats brings the sample to 72 deg and holds the sample at 72 deg for 5 min.End of PCR. Hold 4 deg Stores your sample at 4Deg.  Hope it helps. Sparrow  

jacksparrow · Sep 28, 2011 7:33 PM

I guess question is what happens to samples biochemically..rather than just heat and cool down. So, Before I go on .I assume you have DNA template......Forward and reverse oligos, polymerase and dNTPs at right amount (oh ya, buffer, mg++ too),  then,  lid 85deg ; Wait; Auto--> Pre heat.and lid is always at 85, while the samples are at varied temp 95deg 5min--> denature the DNA  95deg 30 sec-->denature the DNA 40deg 60 sec-->>attach the forward and reverse oligo's , It may actually vary according to melting temp of oligo, isn't 40 too low...may get some unwanted items tooo  72deg 30 sec-->extention , work of polymerase to extend oligo by adding DNTPs Goto 2 rep 40 times -> repeat 40 times, so, 2**40 fragments. 72deg 5 minutes -->> final extention and stabalise  Hold 4 deg--> hold for temporary storage, in case you don't come back in time to store the plate in refrigerator after you go for some coffee or beer......

shivanagar · Sep 28, 2011 9:45 PM

Shiva nagar is i guess right, 40 degrees is too low for a 20 mer primer with workable proportion of GC and AT also depends on what enzyme you are using, Taq, pfu or phusion., kappa etc  phusion requires more Tm and pfu less. In either case 40 is low you are expected to get 1. primer binding to itself 2. more non specific product 3. no product at all read the answers above from other users if you are looking for a basic PCR reaction mechanism

sYaKuuRiolAKU_nchImb · Sep 28, 2011 10:04 PM

Thanks !

aakashconky · Sep 28, 2011 10:29 PM

 @aakashconky timilai chine jasto lagyo...genetics class kasto bhai ra cha ta ..ha ha :P 

DHaRaNe-DADA · Sep 28, 2011 11:22 PM

Maile pani timilai ekchoti Mai Chine, Jaso taso chali ra cha !

aakashconky · Sep 28, 2011 11:37 PM