The host strain used for a specific template preparation can impact template quality:

1. DH5 alpha host strains consistently produce good results.
2. HB101, MV1190, JM109 and XL1 Blue host strains show some variability in result quality. XL1 Blue grows slower than most strains and can lead to decreased DNA yields and it does not respond to TB as do other strains (only showing a 2-3 fold increase in cell number per ml).
3. JM101 is not recommended.

Note: Template preparation or purification procedures which involve the use of phenol or chloroform should be avoided if possible. If use of phenol or chloroform can not be avoided an additional ethanol precipitation is recommended.