Does't matter which company your using and check the trypsin concentration for banding.

Ask this question to Trimurti Scientific Varanasi they will answer you in a right way.

I used karyomax colcemid from GibcoBRL and for g-banding wright's stain. However, as Rajiv said, doesn't matter the company. Time culturing with colcemid depend on the kind of cells are you using... 

Please be more specific. Usually time vs. temperature is crucial for G banding. Also: type of culture and examined specimen.

For Colcemid and colchicine,Trypsin EDTA  SIgma chemicals rest of cutlture medias are from HI Media and any other companies. It doesn;t matter.

Sigma and HI Media

Sometimes company matters a lot. For high analytical grade reagents and chemicals I think Merck and HI Media are the best in the business although it will cost you a little more. 

I am used to Sigma products. They have always proved quite reliable. Some people may be used to other good products that are different from the one I use.. What matters is which standard product is accessible to you.

of course, sometimes matters.

You need a goog quality metaphases for banding and recent slides (Just aged for a day a 90°C x1h or max. a week RT). I suggest You try higher concentrations of trypsin or more timen of trypsinization, may be from 0,1%  up to 0,2% , and the times from 5" up to 35".

Dear Dr.Sahu

I used Sigma product but at first, you should be sure about pretreatments to get high rate metaphasic cells and I agree with Yesica. If cells are not in metaphase, absolutely you dont have any observation.

Before banding you can test your plate by direct observation then if your pretreatment okay you will perform the banding.

Good luck