Should I use my own T4 DNA ligase for cloning into pSpark DNA cloning systems?
A10. Yes, provided it is a very high quality T4 DNA ligase. We have developed one of the best T4 DNA ligases available today on the market, that is, a highly active ligase with the lowest nuclease activity of any T4 DNA ligase you can find anywhere. If you use another T4 DNA ligase please check both the total number of white colonies and the ratio of white positive colonies to blue negative colonies using the supplied Control Insert. This ratio is about 100 for the supplied T4 DNA ligase. If you obtain less than 1000 white colonies (using cells with 4×107 cfu/g) and a ratio of less than 20 then maybe our T4 DNA ligase can help you in your laboratory.
