Skip to main content

Table 1 Influence of different parameters on transformation efficiency.

From: Stable nuclear transformation of Gonium pectorale

Parameter and parameter specification Efficiency
Transformation method  
glassbeads (untreated cells) -
glassbeads (pretreated with protease) -
particle gun (homemade, without vacuum chamber) + +
particle gun (PDS-1000/He biolistic device, with vacuum chamber) + + + + +
Material of microprojectiles  
gold + + + + +
tungsten + +
Size of microprojectiles  
0.6 μm in diameter + + + + +
1.0 μm in diameter +
1.6 μm in diameter -
Selectable marker plasmid  
paphG + +
pPmr3 + + + + +
promoterless aphVIII (+)
Coating of microprojectiles  
plasmid-DNA/microcarrier/NaAc/EtOH-precipitation + + +
plasmid-DNA/microcarrier/CaCl2/spermidine/EtOH-precipitation + + + + +
Target cells  
resuspended in as less liquid as possible; spread in an empty Petri dish -
immobilized on moist filter paper; more or less free of liquid + + +
immobilized on cellulose acetate membrane filter; almost free of liquid + + + + +
Burst pressure of rupture disks  
450 psi -
650 psi -
900 psi +
1100 psi + + + + +
1350 psi + +
Rupture disk-macrocarrier distance  
8 mm + + + + +
16 mm + +
Macrocarrier-stopping screen distance  
7 mm + + + + +
12 mm + + + +
18 mm + + +
Stopping screen-target cell distance  
6 cm + + + + +
11 cm + +
18 cm -
Chamber evacuation  
(almost) no evacuation + +
15 inch Hg + +
27 inch Hg + + + + +
Cultivation after particle bombardment  
on agar plates -
in liquid medium + + + + +
  1. Within each subgroup, the condition that gave the largest number of transformants was set to "+ + + + +"; there is a "-" when no transformants were recovered. The data allow just a qualitative estimation, because a) they were obtained under varying other conditions in the course of optimization, b) poor results disqualified a condition without rechecking, and c) some of the transformants might be false-positives as only a few were analyzed in detail.