BIO RAD PTC-200 Operation Manual page 98

Problem
No reaction products
obtained.
Cause
Wrong protocol used.
Protocol contains a wrong value.
Reaction component omitted from
mixture.
Denaturation temperature too
low.
Annealing temperature too high for
primers.
Wrong temperature control method
used.
Probe failed, causing machine to
run protocol under calculated
control.
Probe not filled with correct
amount of oil.
Reaction mix contains an inhibitor
(e.g., heme from blood).
Reaction vessels not making good
thermal contact with sample block.
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Troubleshooting
Action
Re-run reaction using correct
protocol.
Use List utility to check protocol's
temperature control method, tem-
peratures, and times.
Check reaction assembly protocol,
ensuring that mixture contains
appropriate components in correct
concentrations.
Use >92°C for denaturation.
Check for appropriate annealing
temperatures of primers, using
available computer programs or
empirical testing.
Use List utility to check tempera-
ture control method for protocol;
change if needed.
Check screen for probe failure
error message. Probe may need
servicing or replacing. Contact
Bio-Rad or your local distributor.
Fill probe tube with correct amount
of oil. (see p. 4-11).
Spike a complete reaction mix with
a control template and primer set.
Use only high-quality tubes/plates
that fit block snugly. Ensure that
wells are free of foreign materials
that would interfere with tube/plate
seating.
11-7