The ninhydrin reaction, one of the most important method of detecting amino acids, both technically and historically, has been conventionally used to detect their microgram amounts. When amino acids with a free alpha amino groups are treated with an excess of ninhydrin, they yield a purple colored product.
Update January 19: Amazon has increased the monthly price of Amazon Prime from $10.99 to $12.99 for those who opt for the month-to-month plan. However, the annual price remains untouched at $99 per year, which makes it the better option for avid Amazon shoppers.
When Google starts paying for my hulu, Netflix or Amazon prime, I will change to them. :). Netflix service runs $8.99 per month â which comes out to $107.88 a year â while Amazon Prime is $99 per year. Hulu Plus is $7.99 a month, for the year that equals 95.88. Amazon Prime charges $99 per year for a membership (which equals $8.25 per month), making it very similar to the above options in terms of price. 2  You also get additional benefits including free two-day shipping for purchases made on Amazon.com.