Charcteristics involving Plasmids

1. It must be smaller (40 kb), supercoiled, covalently closed down spherical (CCC) Geonomics and exist for extrachromosomal aspect.

2. It must carry a various cloning site and polycloning location regarding installation of the gene of great interest.

3. It needs to possess atleast 2 selectable markers one of which can be an anti-biotic opposition gene.

4. It must be within good sized quantities for each cell.

5. It must have an source of duplication.

6. It mayor may not include a promoter expressing the actual gene of great interest.

Plasmids tend to be classified into different teams based on several attributes.

Based upon the ability to get familiar with conjugation, plasmids are of two types. Conjugative plasmids are those which take component in conjugation. They've tra genetics which help in conjugation, e.g. P. Plasmids which lack options are called as non conjugative plasmid DNA, e.g. pBR 322.

Classification associated with Plasmids in Bacterial

Classification associated with Plasmids - Based upon the number of duplicates for each cellular, plasmids tend to be categorized into two sorts.

1. Stringent plasmids

These plasmids exist in small numbers, i.e. <100 duplicates/cellular. Stringent plasmid is under the particular control associated with bacterial genome for replication and segregation. Generally, conjunctive plasmids tend to be mostly stringent plasmids.

2. Relaxed plasmids

These plasmids exist in bigamounts, i.e., > 100 duplicates/cellular. Relaxed plasmid is actuallynot under the actual control associated with bacterial genome for replication and segregation. Generally, relaxed plasmids tend to be of low molecular weight and most associated with them are usually associated with the non conjugative type.

The most widely used method to find the particular copy number regarding the plasmid is to estimate the amount of enzyme encoded by genes present in the plasmid. For example, J3-lactamase activity can be measured if the actual plasmid specifies ampicillin resistance.

Sometimes plasmids are usually also labeled into compatible groups, based after plasmid incompatibility. Plasmid incompatibility is the particular inability associated with two different plasmids to co exist in the same cell in the particular absence regarding selection pressure. But this method is not widely used.