Assuming that you don't have your name on any property, you will be able to protect that small of an amount in the joint checking account when you file for bankruptcy. I encourage you to seek a consultation from a bankruptcy attorney to consider all apects of your situation. Your husband would not have to file for bankruptcy, you could file on your own.
This message is intended for informational purposes only. It is impossible to consider all relevant facts from a message board question. No attorney-client relationship has been created. Readers should seek a personal legal consultation with an attorney of their choice for the most accurate advice.
The bank account will still be considered 1/2 yours and 1/2 your husband's regardless of the amount each contributed. This bank account shouldn't be a problem. There is a small enough balance that it should be protected in bankruptcy. If you do not have joint debts I agree with the previous contributor that you could file by yourself.
The only time I have seen joint accounts become an issue is where a debtor has an account with a large amount in it and then turns this into a joint account to "split the account" and then files for bankruptcy. The trustee may look at this as a fraudulent transfer and seek to take more money than just the debtor's half. In this case they will use what is called tracing to determine the source of the money. In Bankruptcy you cannot just transfer title in order to protect assets, the trustee has powers allowing him/her to void such transfers and bring the assets back into the estate. You should find out what the "lookback" period is in your state to see how far back they can go.
You should contact an Bankruptcy attorney regarding this issue.