Plating colonies on 10cm dishes, either for titering or for isolating clones, is a resource intensive process. Eliminate some of the tedium and expense by reducing the scale. Serial dilutions are performed in a 96 well plate filled with bacterial growth media e.g. 270uL per well, transferring 30uL down the columns for a 1:10 dilution per row. Next, using a 96 channel Biomek NX, 10uL of dilute bacteria from each well are deposited on the surface of an Omni plate filled with 60mL LB agar + AMP at 100ug/mL. Dilute such that counts are in the range of 5 to 20 per spot.
Nunc cat# 267060
Nunc cat# 242811 OmniTray Single Well w/lid 86x128mm (pictured below)
A single Omniplate can substitute for 96 10cm dishes, though in practice many of the Omniplate regions will not be countable. Below are some images of colony growth on the first three rows of an Omni plate.
Close up of 9 regions, with counts indicated in white:
Comparison of counts from a 10cm dish to counts from an Omniplate. Expected counts are an estimate based on OD600.
OD600 estimate is >100 fold off.
Calculated titers. Note that results are more consistent with the wells containing a higher number of counts - Row B:
